Publications

## Publications

The third data release of Gaia has provided low-resolution spectra for ~100 000 white dwarfs (WDs) that, together with the excellent photometry and astrometry, represent an unrivalled benchmark for the study of this population. In this work, we first built a highly complete volume-limited sample consisting in 12 718 WDs within 100 pc from the Sun. The use of Virtual Observatory Spectral energy distribution Analyzer tool allowed us to perform an automated fitting of their spectral energy distributions to different atmospheric models. In particular, the use of spectrally derived Javalambre-Physics of the Accelerating Universe Astrophysical Survey photometry from Gaia spectra led to the classification of DA and non-DA WDs with an accuracy >90 per cent, tested in already spectroscopically labelled objects. The excellent performance achieved was extended to practically the whole population of WDs with effective temperatures above 5500 K. Our results show that while the A branch of the Gaia WD Hertzsprung-Russell diagram is practically populated by DA WDs, the B branch is largely formed by non-DAs (65 per cent). The remaining 35 per cent of DAs within the B branch implies a second peak at ~0.8 M⊙ in the DA mass distribution. Additionally, the Q branch and its extension to lower temperatures can be observed for both DA and non-DA objects due to core crystallization. Finally, we derived a detailed spectral evolution function, which confirms a slow increase of the fraction of non-DAs as the effective temperature decreases down to 10 500 K, where it reaches a maximum of 36 per cent and then decreases for lower temperatures down to ~31 per cent.

With a unique set of 54 overlapping narrow-band and two broader filters covering the entire optical range, the incoming Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will provide a great opportunity for stellar physics and near-field cosmology. In this work, we use the miniJPAS data in 56 J-PAS filters and 4 complementary SDSS-like filters to explore and prove the potential of the J-PAS filter system in characterizing stars and deriving their atmospheric parameters. We obtain estimates for the effective temperature with a good precision (<150 K) from spectral energy distribution fitting. We have constructed the metallicity-dependent stellar loci in 59 colours for the miniJPAS FGK dwarf stars, after correcting certain systematic errors in flat-fielding. The very blue colours, including uJAVA - r, J0378 - r, J0390 - r, uJPAS - r, show the strongest metallicity dependence, around 0.25 mag dex-1. The sensitivities decrease to about 0.1 mag dex-1 for the J0400 - r, J0410 - r, and J0420 - r colours. The locus fitting residuals show peaks at the J0390, J0430, J0510, and J0520 filters, suggesting that individual elemental abundances such as [Ca/Fe], [C/Fe], and [Mg/Fe] can also be determined from the J-PAS photometry. Via stellar loci, we have achieved a typical metallicity precision of 0.1 dex. The miniJPAS filters also demonstrate strong potential in discriminating dwarfs and giants, particularly the J0520 and J0510 filters. Our results demonstrate the power of the J-PAS filter system in stellar parameter determinations and the huge potential of the coming J-PAS survey in stellar and Galactic studies.

The Javalambre Photometric Local Universe Survey (J-PLUS) is an ongoing 12 band photometric optical survey, observing thousands of square degrees of the Northern Hemisphere from the dedicated JAST80 telescope at the Observatorio Astrofísico de Javalambre (OAJ). Observational strategy is a critical point in this large survey. To plan the best observations, it is necessary to select pointings depending on object visibility, the pointing priority and status and location and phase of the Moon. In this context, the J-PLUS Tracking Tool, a web application, has been implemented, which includes tools to plan the best observations, as well as tools to create the command files for the telescope; to track the observations; and to know the status of the survey. In this environment, robustness is an important point. To obtain it, a feedback software system has been implemented. This software automatically decides and marks which observations are valid or which must be repeated. It bases its decision on the data obtained from the data management pipeline database using a complex system of pointing and filter statuses. This contribution presents J-PLUS Tracking Tool and all feedback software system.

Context. The Lyα emission is an important tracer of neutral gas in a circum-galactic medium (CGM) around high-z quasi-stellar objects (QSOs). The origin of Lyα emission around QSOs is still under debate, bringing on significant implications for galaxy formation and evolution. Aims: In this paper, we study Lyα nebulae around two high redshift QSOs, SDSS J141935.58+525710.7 at z = 3.218 (hereafter QSO1) and SDSS J141813.40+525240.4 at z = 3.287 (hereafter QSO2), from the miniJPAS survey within the All-wavelength Extended Groth Strip International Survey (AEGIS) field. Methods: Using the contiguous narrow-band (NB) images from the miniJPAS survey and Sloan Digital Sky Survey (SDSS) spectra, we analyzed their morphology, nature, and origin. Results: We report the serendipitous detection of double-core Lyα morphology around two QSOs, which is rarely seen among other QSOs. The separations of the two Lyα cores are 11.07 ± 2.26 kpcs (1.47 ± 0.3″) and 9.73 ± 1.55 kpcs (1.31 ± 0.21″), with Lyα line luminosities of ∼3.35 × 1044 erg s−1 and ∼6.99 × 1044 erg s −1 for QSO1 and QSO2, respectively. The miniJPAS NB images show evidence of extended Lyα and CIV morphology for both QSOs and extended HeII morphology for QSO1. Conclusions: These two QSOs may be potential candidates for the new enormous Lyman alpha nebula (ELAN) found from the miniJPAS survey due to their extended morphology in the shallow depth and relatively high Lyα luminosities. We suggest that galactic outflows are the major powering mechanism for the double-core Lyα morphology. Considering the relatively shallow exposures of miniJPAS, the objects found here could merely form the cusp of a promising number of such objects that will be uncovered in the upcoming full Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) survey and deep integral field units (IFU) observations with 8-10 m telescopes will be essential for constraining the underlying physical mechanism that is responsible for the double-cored morphology.

Context. The importance of photometric galaxy redshift estimation is rapidly increasing with the development of specialised powerful observational facilities. Aims: We develop a new photometric redshift estimation workflow TOPz to provide reliable and efficient redshift estimations for the upcoming large-scale survey J-PAS which will observe 8500 deg2 of the northern sky through 54 narrow-band filters. Methods: TOPz relies on template-based photo-z estimation with some added J-PAS specific features and possibilities. We present TOPz performance on data from the miniJPAS survey, a precursor to the J-PAS survey with an identical filter system. First, we generated spectral templates based on the miniJPAS sources using the synthetic galaxy spectrum generation software CIGALE. Then we applied corrections to the input photometry by minimising systematic offsets from the template flux in each filter. To assess the accuracy of the redshift estimation, we used spectroscopic redshifts from the DEEP2, DEEP3, and SDSS surveys, available for 1989 miniJPAS galaxies with r < 22 magAB. We also tested how the choice and number of input templates, photo-z priors, and photometric corrections affect the TOPz redshift accuracy. Results: The general performance of the combination of miniJPAS data and the TOPz workflow fulfills the expectations for J-PAS redshift accuracy. Similarly to previous estimates, we find that 38.6% of galaxies with r < 22 mag reach the J-PAS redshift accuracy goal of dz/(1 + z) < 0.003. Limiting the number of spectra in the template set improves the redshift accuracy up to 5%, especially for fainter, noise-dominated sources. Further improvements will be possible once the actual J-PAS data become available.

Context. Over the past decades, several studies have discovered a population of galaxies that undergo very strong star formation events. They are called extreme emission line galaxies (EELGs). Aims: We exploit the capabilities of the Javalambre Photometric Local Universe Survey (J-PLUS), a wide-field multifilter survey, with which 2000 square degrees of the northern sky are already observed. We use it to identify EELGs at low redshift by their [OIII]5007 emission line. We intend to provide a more complete, deep, and less biased sample of local EELGs. Methods: We selected objects with an excess of flux in the J-PLUS medium-band J0515 filter, which covers the [OIII] line at z < 0.06. We removed contaminants (stars and higher-redshift systems) using J-PLUS and WISE infrared photometry, with SDSS spectra as a benchmark. We performed spectral energy distribution fitting to estimate the physical properties of the galaxies: line fluxes, equivalent widths (EWs), masses, stellar population ages, and so on. Results: We identify 466 EELGs at z < 0.06 with [OIII] EW over 300 Å and an r-band magnitude below 20, of which 411 were previously unknown. Most show compact morphologies, low stellar masses (log(M⋆/M⊙) ∼ 8.13−0.58+0.61), low dust extinction (E(B−V) ∼ 0.1−0.1+0.2), and very young bursts of star formation (3.0−2.0+2.7 Myr). Our method is up to ∼20 times more efficient in detecting EELGs per Mpc3 than broadband surveys, and it is as complete as magnitude-limited spectroscopic surveys (but reaches fainter objects). The sample is not directly biased against strong Hα emitters, in contrast with works using broadband surveys. Conclusions: We demonstrate that J-PLUS can identify a large sample of previously unknown EELGs showing unique properties following a clear selection process. A fraction of the EELGs are probably similar to the first galaxies in the Universe, but they are at a much lower redshift, which makes them ideal targets for follow-up studies. Full Tables 3 and 4 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/668/A60

Within our program of physical characterization of trans-Neptunian objects and centaurs, we predicted a stellar occultation by the centaur (54598) Bienor to occur on January 11, 2019, with good observability potential. We obtained high accuracy astrometric data to refine the prediction, resulting in a shadow path favorable for the Iberian Peninsula. This encouraged us to carry out an occultation observation campaign that resulted in five positive detections from four observing sites. This is the fourth centaur for which a multichord (more than two chords) stellar occultation has been observed so far, the other three being (2060) Chiron, (10199) Chariklo, and (95626) 2002 GZ 3232 . From the analysis of the occultation chords, combined with the rotational light curve obtained shortly after the occultation, we determined that Bienor has an area-equivalent diameter of 150±20150±20 km. This diameter is ∼30∼30 km smaller than the one obtained from thermal measurements. The position angle of the short axis of the best fitting ellipse obtained through the analysis of the stellar occultation does not match that of the spin axis derived from long-term photometric models. We also detected a strong irregularity in one of the minima of the rotational light curve that is present no matter the aspect angle at which the observations were done. We present different scenarios to reconcile the results from the different techniques. We did not detect secondary drops related to potential rings or satellites. Nonetheless, similar rings in size to that of Chariklo's cannot be discarded due to low data accuracy.

Context. Multifilter photometry from large sky surveys is commonly used to assign asteroid taxonomic types and study various problems in planetary science. To maximize the science output of those surveys, it is important to use methods that best link the spectro-photometric measurements to asteroid taxonomy. Aims: We aim to determine which machine learning methods are the most suitable for the taxonomic classification for various sky surveys. Methods: We utilized five machine learning supervised classifiers: logistic regression, naive Bayes, support vector machines (SVMs), gradient boosting, and MultiLayer Perceptrons (MLPs). Those methods were found to reproduce the Bus-DeMeo taxonomy at various rates depending on the set of filters used by each survey. We report several evaluation metrics for a comprehensive comparison (prediction accuracy, balanced accuracy, F1 score, and the Matthews correlation coefficient) for 11 surveys and space missions. Results: Among the methods analyzed, multilayer perception and gradient boosting achieved the highest accuracy and naive Bayes achieved the lowest accuracy in taxonomic prediction across all surveys. We found that selecting the right machine learning algorithm can improve the success rate by a factor of >2. The best balanced accuracy (~85% for a taxonomic type prediction) was found for the Visible and Infrared Survey telescope for Astronomy (VISTA) and the ESA Euclid mission surveys where broadband filters best map the 1 µm and 2 µm olivine and pyroxene absorption bands. Conclusions: To achieve the highest accuracy in the taxonomic type prediction based on multifilter photometric measurements, we recommend the use of gradient boosting and MLP optimized for each survey. This can improve the overall success rate even when compared with naive Bayes. A merger of different datasets can further boost the prediction accuracy. For the combination of the Legacy Survey of Space and Time and VISTA survey, we achieved 90% for the taxonomic type prediction.

In this series of papers, we employ several machine learning (ML) methods to classify the point-like sources from the miniJPAS catalogue, and identify quasar candidates. Since no representative sample of spectroscopically confirmed sources exists at present to train these ML algorithms, we rely on mock catalogues. In this first paper we develop a pipeline to compute synthetic photometry of quasars, galaxies and stars using spectra of objects targeted as quasars in the Sloan Digital Sky Survey. To match the same depths and signal-to-noise ratio distributions in all bands expected for miniJPAS point sources in the range 17.5 ≤ r < 24, we augment our sample of available spectra by shifting the original r-band magnitude distributions towards the faint end, ensure that the relative incidence rates of the different objects are distributed according to their respective luminosity functions, and perform a thorough modeling of the noise distribution in each filter, by sampling the flux variance either from Gaussian realizations with given widths, or from combinations of Gaussian functions. Finally, we also add in the mocks the patterns of non-detections which are present in all real observations. Although the mock catalogues presented in this work are a first step towards simulated data sets that match the properties of the miniJPAS observations, these mocks can be adapted to serve the purposes of other photometric surveys.

The miniJPAS survey has observed ∼1 deg2 of the AEGIS field with 60 bands (spectral resolution of R ∼ 60) in order to demonstrate the scientific potential of the Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS), which will map ∼8000 deg2 of the northern sky over the coming years. In particular, this paper demonstrates the potential of J-PAS in detecting groups with mass of up to 1013 M⊙ and in characterising their galaxy populations up to z ∼ 1. The parametric code BaySeAGal is used to derive the stellar population properties by fitting the J-PAS spectral energy distribution (SED) of the galaxy members in 80 groups at z ≤ 0.8 previously detected by the AMICO code, and of a galaxy field sample retrieved from the whole miniJPAS down to r < 22.75 (AB). Blue, red, quiescent, and transition (blue quiescent or green valley) galaxy populations are identified through their rest-frame (extinction-corrected) (u − r)int colour, galaxy stellar mass (M⋆), and specific star formation rate (sSFR). We measure the abundance of these galaxies as a function of M⋆ and environment in order to investigate the role that groups play in quenching star formation. Our findings are as follows. (i) The fraction of red and quiescent galaxies in groups increases with M⋆ and is always higher in groups (28% on average) than in the field (5%). (ii) The quenched fraction excess (QFE) in groups shows a strong dependence on M⋆, and increases from a few percent for galaxies with M⋆ < 1010 M⊙ to higher than 60% for galaxies with M⋆ > 3 × 1011 M⊙. (iii) The abundance excess of transition galaxies in groups shows a modest dependence on M⋆, being 5%-10% for galaxies with M⋆ < 1011 M⊙. (iv) The fading timescale, defined as the time that galaxies in groups spend in the transition phase, is very short (< 1.5 Gyr), indicating that the star formation of galaxies in groups declines very rapidly. (v) The evolution of the galaxy quenching rate in groups shows a modest but significant evolution since z ∼ 0.8. This latter result is compatible with the expected evolution with constant QFE = 0.4, which has been previously measured for satellites in the nearby Universe, as traced by SDSS. Further, this evolution is consistent with a scenario where the low-mass star forming galaxies in clusters at z = 1-1.4 are environmentally quenched, as previously reported by other surveys.

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a photometric survey that is poised to scan several thousands of square degrees of the sky. It will use 54 narrow-band filters, combining the benefits of low-resolution spectra and photometry. Its offshoot, miniJPAS, is a 1 deg2 survey that uses J-PAS filter system with the Pathfinder camera. In this work, we study mJPC2470-1771, the most massive cluster detected in miniJPAS. We survey the stellar population properties of the members, their star formation rates (SFR), star formation histories (SFH), the emission line galaxy (ELG) population, spatial distribution of these properties, and the ensuing effects of the environment. This work shows the power of J-PAS to study the role of environment in galaxy evolution. We used a spectral energy distribution (SED) fitting code to derive the stellar population properties of the galaxy members: stellar mass, extinction, metallicity, (u − r)res and (u − r)int colours, mass-weighted age, the SFH that is parametrised by a delayed-τ model (τ, t0), and SFRs. We used artificial neural networks for the identification of the ELG population via the detection of the Hα, [NII], Hβ, and [OIII] nebular emission. We used the Ew(Hα)-[NII] (WHAN) and [OIII]/Hα-[NII]/Hα (BPT) diagrams to separate them into individual star-forming galaxies and AGNs. We find that the fraction of red galaxies increases with the cluster-centric radius; and at 0.5R200 the red and blue fractions are both equal. The redder, more metallic, and more massive galaxies tend to be inside the central part of the cluster, whereas blue, less metallic, and less massive galaxies are mainly located outside of the inner 0.5R200. We selected 49 ELG, with 65.3% of them likely to be star-forming galaxies, dominated by blue galaxies, and 24% likely to have an AGN (Seyfert or LINER galaxies). The rest are difficult to classify and are most likely composite galaxies. These latter galaxies are red, and their abundance decreases with the cluster-centric radius; in contrast, the fraction of star-forming galaxies increases outwards up to R200. Our results are compatible with an scenario in which galaxy members were formed roughly at the same epoch, but blue galaxies have had more recent star formation episodes, and they are quenching out from within the cluster centre. The spatial distribution of red galaxies and their properties suggest that they were quenched prior to the cluster accretion or an earlier cluster accretion epoch. AGN feedback or mass might also stand as an obstacle in the quenching of these galaxies.

Globular clusters (GCs) are proxies of the formation assemblies of their host galaxies. However, few studies exist targeting GC systems of spiral galaxies up to several effective radii. Through 12-band Javalambre Photometric Local Universe Survey (J-PLUS) imaging, we study the point sources around the M 81/M 82/NGC 3077 triplet in search of new GC candidates. We develop a tailored classification scheme to search for GC candidates based on their similarity to known GCs via a principal component analysis projection. Our method accounts for missing data and photometric errors. We report 642 new GC candidates in a region of 3.5 deg2 around the triplet, ranked according to their Gaia astrometric proper motions when available. We find tantalizing evidence for an overdensity of GC candidate sources forming a bridge connecting M 81 and M 82. Finally, the spatial distribution of the GC candidates (g - i) colours is consistent with halo/intra-cluster GCs, i.e. it gets bluer as they get further from the closest galaxy in the field. We further employ a regression-tree-based model to estimate the metallicity distribution of the GC candidates based on their J-PLUS bands. The metallicity distribution of the sample candidates is broad and displays a bump towards the metal-rich end. Our list increases the population of GC candidates around the triplet by threefold, stresses the usefulness of multiband surveys in finding these objects, and provides a testbed for further studies analysing their spatial distribution around nearby (spirals) galaxies.

Context. Ultracool dwarfs (UCDs) comprise the lowest mass members of the stellar population and brown dwarfs, from M7 V to cooler objects with L, T, and Y spectral types. Most of them have been discovered using wide-field imaging surveys, for which the Virtual Observatory (VO) has proven to be of great utility. Aims: We aim to perform a search for UCDs in the entire Javalambre Photometric Local Universe Survey (J-PLUS) second data release (2176 deg2) following a VO methodology. We also explore the ability to reproduce this search with a purely machine learning (ML)-based methodology that relies solely on J-PLUS photometry. Methods: We followed three different approaches based on parallaxes, proper motions, and colours, respectively, using the VOSA tool to estimate the effective temperatures and complement J-PLUS photometry with other catalogues in the optical and infrared. For the ML methodology, we built a two-step method based on principal component analysis and support vector machine algorithms. Results: We identified a total of 7827 new candidate UCDs, which represents an increase of about 135% in the number of UCDs reported in the sky coverage of the J-PLUS second data release. Among the candidate UCDs, we found 122 possible unresolved binary systems, 78 wide multiple systems, and 48 objects with a high Bayesian probability of belonging to a young association. We also identified four objects with strong excess in the filter corresponding to the Ca II H and K emission lines and four other objects with excess emission in the Hα filter. Follow-up spectroscopic observations of two of them indicate they are normal late-M dwarfs. With the ML approach, we obtained a recall score of 92% and 91% in the 20 × 20 deg2 regions used for testing and blind testing, respectively. Conclusions: We consolidated the proposed search methodology for UCDs, which will be used in deeper and larger upcoming surveys such as J-PAS and Euclid. We concluded that the ML methodology is more efficient in the sense that it allows for a larger number of true negatives to be discarded prior to analysis with VOSA, although it is more photometrically restrictive.

Aims: We analyze the white dwarf population in miniJPAS, the first square degree observed with 56 medium-band, 145 Å in width optical filters by the Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS), to provide a data-based forecast for the white dwarf science with low-resolution (R ∼ 50) photo-spectra. Methods: We define the sample of the bluest point-like sources in miniJPAS with r < 21.5 mag, a point-like probability larger than 0.5, (u − r)< 0.80 mag, and (g − i)< 0.25 mag. This sample comprises 33 sources with spectroscopic information: 11 white dwarfs and 22 quasi-stellar objects (QSOs). We estimate the effective temperature (Teff), the surface gravity, and the composition of the white dwarf population by a Bayesian fitting to the observed photo-spectra. Results: The miniJPAS data are sensitive to the Balmer series and the presence of polluting metals. Our results, combined with those from the Javalambre Photometric Local Universe Survey (J-PLUS) which has a lower spectral resolution but has already observed thousands of white dwarfs, suggest that J-PAS photometry would permit - down to r ∼ 21.5 mag and at least for sources with 7000 < Teff < 22 000 K - both the classification of the observed white dwarfs into H-dominated and He-dominated with 99% confidence and the detection of calcium absorption for equivalent widths larger than 15 Å. The effective temperature is estimated with a 2% uncertainty, which is close to the 1% from spectroscopy. A precise estimation of the surface gravity depends on the available parallax information. In addition, the white dwarf population at Teff > 7000 K can be segregated from the bluest extragalactic QSOs, providing a clean sample based on optical photometry alone. Conclusions: The J-PAS low-resolution photo-spectra would produce precise effective temperatures and atmospheric compositions for white dwarfs, complementing the data from Gaia. J-PAS will also detect and characterize new white dwarfs beyond the Gaia magnitude limit, providing faint candidates for spectroscopic follow-up.

Context. Galaxies with extreme emission lines (EELGs) may play a key role in the evolution of the Universe, as well as in our understanding of the star formation process itself. For this reason an accurate determination of their spatial density and fundamental properties in different epochs of the Universe will constitute a unique perspective towards a comprehensive picture of the interplay between star formation and mass assembly in galaxies. In addition to this, EELGs are also interesting in order to explain the reionization of the Universe, since their interstellar medium (ISM) could be leaking ionizing photons, and thus they could be low z, analogous of extreme galaxies at high z. Aims: This paper presents a method to obtain a census of EELGs over a large area of the sky by detecting galaxies with rest-frame equivalent widths ≥300 Å in the emission lines [O II]λλ3727,3729Å, [O III]λ5007Å, and Hα. For this, we aim to use the J-PAS survey, which will image an area of ≈8000 deg2 with 56 narrow band filters in the optical. As a pilot study, we present a methodology designed to select EELGs on the miniJPAS images, which use the same filter dataset as J-PAS, and thus will be exportable to this larger survey. Methods: We make use of the miniJPAS survey data, conceived as a proof of concept of J-PAS, and covering an area of ≈1 deg2. Objects were detected in the rSDSS images and selected by imposing a condition on the flux in a given narrow-band J-PAS filter with respect to the contiguous ones, which is analogous to requiring an observed equivalent width larger than 300 Å in a certain emission line within the filter bandwidth. The selected sources were then classified as galaxies or quasi-stellar objects (QSOs) after a comparison of their miniJPAS fluxes with those of a spectral database of objects known to present strong emission lines. This comparison also provided a redshift for each source, which turned out to be consistent with the spectroscopic redshifts when available (|Δz/(1 + zspec)| ≤ 0.01). Results: The selected candidates were found to show a compact appearance in the optical images, some of them even being classified as point-like sources according to their stellarity index. After discarding sources classified as QSOs, a total of 17 sources turned out to exhibit EW0 ≥ 300 Å in at least one emission line, thus constituting our final list of EELGs. Our counts are fairly consistent with those of other samples of EELGs in the literature, although there are some differences, which were expected due to biases resulting from different selection criteria.

The Centro de Estudios de Física del Cosmos de Aragón (CEFCA) is carrying out from the Observatorio Astrofísico de Javalambre (OAJ, Teruel, Spain) two large area multiband photometric sky surveys, J-PLUS and J-PAS, covering the entire optical spectrum using narrow and broad band filters. J-PAS and J-PLUS include coadded and individual frame images and dual and single catalogue data. To publish all of this data, the CEFCA catalogues portal has been implemented offering web user interface services, as well, as Virtual Observatory (VO) services. This contribution presents the effort and work done in the CEFCA Catalogues Portal to enhance data publication of these large surveys following FAIR principles to increase data value and maximize research efficiency. It presents how FAIR principles have been achieved and improved with the implementation and publishing of the CEFCA Catalogues Publishing Registry, the use of VO services, their validation and improving processes and the effort made to offer data to improve provenance information.

Context. Stellar parameters are among the most important characteristics in studies of stars which, in traditional methods, are based on atmosphere models. However, time, cost, and brightness limits restrain the efficiency of spectral observations. The Javalambre Photometric Local Universe Survey (J-PLUS) is an observational campaign that aims to obtain photometry in 12 bands. Owing to its characteristics, J-PLUS data have become a valuable resource for studies of stars. Machine learning provides powerful tools for efficiently analyzing large data sets, such as the one from J-PLUS, and enables us to expand the research domain to stellar parameters. Aims: The main goal of this study is to construct a support vector regression (SVR) algorithm to estimate stellar parameters of the stars in the first data release of the J-PLUS observational campaign. Methods: The training data for the parameters regressions are featured with 12-waveband photometry from J-PLUS and are crossidentified with spectrum-based catalogs. These catalogs are from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, the Apache Point Observatory Galactic Evolution Experiment, and the Sloan Extension for Galactic Understanding and Exploration. We then label them with the stellar effective temperature, the surface gravity, and the metallicity. Ten percent of the sample is held out to apply a blind test. We develop a new method, a multi-model approach, in order to fully take into account the uncertainties of both the magnitudes and the stellar parameters. The method utilizes more than 200 models to apply the uncertainty analysis. Results: We present a catalog of 2 493 424 stars with the root mean square error of 160 K in the effective temperature regression, 0.35 in the surface gravity regression, and 0.25 in the metallicity regression. We also discuss the advantages of this multi-model approach and compare it to other machine-learning methods. Table with the sample of stars and derived parameters is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/664/A38

Context. Scientific interest in studying high-energy transient phenomena in the Universe has risen sharply over the last decade. At present, multiple ground-based survey projects have emerged to continuously monitor the optical (and multi-messenger) transient sky at higher image cadences and covering ever larger portions of the sky every night. These novel approaches are leading to a substantial increase in global alert rates, which need to be handled with care, especially with regard to keeping the level of false alarms as low as possible. Therefore, the standard transient detection pipelines previously designed for narrow field-of-view instruments must now integrate more sophisticated tools to deal with the growing number and diversity of alerts and false alarms. Aims: Deep machine learning algorithms have now proven their efficiency in recognising patterns in images. These methods are now used in astrophysics to perform different classification tasks such as identifying bogus from real transient point-like sources. We explore this method to provide a robust and flexible algorithm that could be included in any kind of transient detection pipeline. Methods: We built a convolutional neural network (CNN) algorithm in order to perform a real or bogus' classification task on transient candidate cutouts (subtraction residuals) provided by different kinds of optical telescopes. The training involved human-supervised labelling of the cutouts, which are split into two balanced data sets with true' and false' point-like source candidates. We tested our CNN model on the candidates produced by two different transient detection pipelines. In addition, we made use of several diagnostic tools to evaluate the classification performance of our CNN models. Results: We show that our CNN algorithm can be successfully trained on a large and diverse array of images on very different pixel scales. In this training process, we did not detect any strong over- or underfitting with the requirement of providing cutouts with a limited size no larger than 50 × 50 pixels. Tested on optical images from four different telescopes and utilising two different transient detection pipelines, our CNN model provides a robust real or bogus' classification performance accuracy from 93% up to 98% for well-classified candidates. The codes and diagnostic tools presented in this paper are available at https://github.com/dcorre/otrain

Commissioning results, on-sky performance and first operations of the Javalambre Panoramic Camera (JPCam) are presented in this paper. JPCam is a 1.2 Gpixel camera deployed on the 2.6m, large field-of-vie Javalambre Survey Telescope (JST250) at the Observatorio Astrofísico Javalambre. JPCam has been conceived to perform J-PAS, a photometric survey of several thousand square degrees of the northern sky in 56 optical bands, 54 of them narrow-band filters (145 ˚A FWHM), contiguous and equi-spaced between 370 and 920nm, producing a low resolution photo-spectrum of every pixel of the observed sky, hence promising crucial breakthroughs in Cosmology and galaxy formation and evolution. JPCam has been designed to maximize field-of-view and wavelength coverage while guaranteeing a high image quality over the entire focal plane. To this aim, JPCam is equipped with a mosaic of 14 9.2k x 9.2k, 10µm pixel, low noise detectors from Teledyne-E2V, providing a FoV of 4.1 square degrees with a plate scale of 0.2267''/pix. In full frame mode, camera electronics allows read times of 10.9s at 633kHz read frequency (16.4s at 400kHz) with a readout noise of 5.5e− (4.3e−). Its filter unit admits 5 filter trays, each mounting 14 filters corresponding to the 14 CCDs of the mosaic and allowing all the J-PAS filters to be permanently installed. To fully optimize image quality, position of JST250 secondary mirror and JPCam focal plane are maintained optically aligned by means of two hexapod systems. To perform this task, JPCam includes 12 auxiliary detectors, 4 for autoguiding and 8 for image quality control through wavefront sensing.

The Observatorio Astrofísico de Javalambre (OAJ†1 ) in Spain is a young astronomical facility, conceived and developed from the beginning as a fully automated observatory with the main goal of optimizing the processes in the scientific and general operation of the Observatory. The OAJ has been particularly conceived for carrying out large sky surveys with two unprecedented telescopes of unusually large fields of view (FoV): the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view. The most immediate objective of the two telescopes for the next years is carrying out two unique photometric surveys of several thousands square degrees, J-PAS†2 and J-PLUS†3 , each of them with a wide range of scientific applications, like e.g. large structure cosmology and Dark Energy, galaxy evolution, supernovae, Milky Way structure, exoplanets, among many others. To do that, JST and JAST are equipped with panoramic cameras under development within the J-PAS collaboration, JPCam and T80Cam respectively, which make use of large format (~ 10k x 10k) CCDs covering the entire focal plane. This paper describes in detail, from operations point of view, a comparison between the detailed cost of the global automation of the Observatory and the standard automation cost for astronomical facilities, in reference to the total investment and highlighting all benefits obtained from this approach and difficulties encountered. The paper also describes the engineering development of the overall facilities and infrastructures for the fully automated observatory and a global overview of current status, pinpointing lessons learned in order to boost observatory operations performance, achieving scientific targets, maintaining quality requirements, but also minimizing operation cost and human resources.

Afterglow radiation in gamma-ray bursts (GRB), extending from the radio band to GeV energies, is produced as a result of the interaction between the relativistic jet and the ambient medium. Although in general the origin of the emission is robustly identified as synchrotron radiation from the shock-accelerated electrons, many aspects remain poorly constrained, such as the role of inverse Compton emission, the particle acceleration mechanism, the properties of the environment and of the GRB jet itself. The extension of the afterglow emission into the TeV band has been discussed and theorized for years, but has eluded for a long time the observations. Recently, the Cherenkov telescopes, MAGIC and H.E.S.S., have unequivocally proven that afterglow radiation is also produced above 100 GeV, up to at least a few TeV. The accessibility of the TeV spectral window will largely improve with the upcoming facility CTA (the Cherenkov Telescope Array). In this review article, we first revise the current model for afterglow emission in GRBs, its limitations and open issues. Then, we describe the recent detections of very high energy emission from GRBs and the origin of this radiation. Implications on the understanding of afterglow radiation and constraints on the physics of the involved processes will be deeply investigated, demonstrating how future observations, especially by the CTA Observatory, are expected to give a key contribution in improving our comprehension of such elusive sources.

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is expected to map thousands of square degrees of the northern sky with 56 narrowband filters (spectral resolution of R ∼ 60) in the upcoming years. This resolution allows us to study emission line galaxies (ELGs) with a minimum equivalent width of 10 Å in the Hα emission line for a median signal-to-noise ratio (S/N) of 5. This will make J-PAS a very competitive and unbiased emission line survey compared to spectroscopic or narrowband surveys with fewer filters. The miniJPAS survey covered 1 deg2, and it used the same photometric system as J-PAS, but the observations were carried out with the pathfinder J-PAS camera. In this work, we identify and characterize the sample of ELGs from miniJPAS with a redshift lower than 0.35, which is the limit to which the Hα line can be observed with the J-PAS filter system. Using a method based on artificial neural networks, we detect the ELG population and measure the equivalent width and flux of the Hα, Hβ, [O III], and [N II] emission lines. We explore the ionization mechanism using the diagrams [OIII]/Hβ versus [NII]/Hα (BPT) and EW(Hα) versus [NII]/Hα (WHAN). We identify 1787 ELGs (83%) from the parent sample (2154 galaxies) in the AEGIS field. For the galaxies with reliable EW values that can be placed in the WHAN diagram (2000 galaxies in total), we obtained that 72.8 ± 0.4%, 17.7 ± 0.4%, and 9.4 ± 0.2% are star-forming (SF), active galactic nucleus (Seyfert), and quiescent galaxies, respectively. The distribution of EW(Hα) is well correlated with the bimodal color distribution of galaxies. Based on the rest-frame (u − r)-stellar mass diagram, 94% of the blue galaxies are SF galaxies, and 97% of the red galaxies are LINERs or passive galaxies. The nebular extinction and star formation rate (SFR) were computed from the Hα and Hβ fluxes. We find that the star formation main sequence is described as log SFR [M⊙ yr−1] = 0.90−0.02+0.02 log M⋆[M⊙]−8.85−0.20+0.19 and has an intrinsic scatter of 0.20−0.01+0.01. The cosmic evolution of the SFR density (ρSFR) is derived at three redshift bins: 0 < z ≤ 0.15, 0.15 < z ≤ 0.25, and 0.25 < z ≤ 0.35, which agrees with previous results that were based on measurements of the Hα emission line. However, we find an offset with respect to other estimates that were based on the star formation history obtained from fitting the spectral energy distribution of the stellar continuum. We discuss the origin of this discrepancy, which is probably a combination of several factors: the escape of ionizing photons, the SFR tracers, and dust attenuation, among others.

Extragalactic globular clusters (GCs) are key objects for studying the formation and evolution of galaxies. The arrival of wide-field surveys such as the Javalambre Photometric Local Universe Survey (J-PLUS) offers new possibilities for the study of GCs. Nevertheless, GCs are not detected a priori by the data reduction pipeline of J-PLUS and, due to its pixel scale, the standard techniques of GCs detection are challenged. To fill this gap, we develop a semi-automatic pipeline to detect GCs in J-PLUS that can also be adapted to similar surveys. As a case study, we use data from the S0 galaxy NGC 1023 and we also study the stellar population content of GC candidates in the galaxy. To detect GCs, our methodology is based on Source Extractor and does not require a previous filtering or modelling of the host galaxy. We study colors and perform spectral energy distribution (SED) analysis on our final GC candidate catalog to obtain stellar population parameters. In NGC 1023, GCFinder identifies 523 GC candidates. We observe evidence of color bimodality in a few broad-band colors but not on narrow-band colors. The SED analysis reveals a clear metallicity bimodality and we observe that narrow-band filters are very useful to constrain metallicities. We also identified a broad age-metallicity relation as well as a wide metallicity distribution that are evidence that NGC 1023 experienced accretion events in the past. It is the first time this kind of study is performed with J-PLUS data. By detecting GC candidates in wide-field images without modeling the light of the galaxy, GCFinder becomes considerably faster, at a marginal loss of centrally-located GC candidates of about 7 percent. As GCFinder is entirely based on Source Extractor, it could be easily incorporated into automated software handling wide-field surveys.

Context. Precise measurements of black hole masses are essential to understanding the coevolution of these sources and their host galaxies. Aims: We develop a novel approach for computing black hole virial masses using measurements of continuum luminosities and emission line widths from partially overlapping, narrow-band observations of quasars; we refer to this technique as single-epoch photometry. Methods: This novel method relies on forward-modelling quasar observations for estimating emission line widths, which enables unbiased measurements even for lines coarsely resolved by narrow-band data. We assess the performance of this technique using quasars from the Sloan Digital Sky Survey (SDSS) observed by the miniJPAS survey, a proof-of-concept project of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) collaboration covering ≃1 deg2 of the northern sky using the 56 J-PAS narrow-band filters. Results: We find remarkable agreement between black hole masses from single-epoch SDSS spectra and single-epoch miniJPAS photometry, with no systematic difference between these and a scatter ranging from 0.4 to 0.07 dex for masses from log(MBH)≃8 to 9.75, respectively. Reverberation mapping studies show that single-epoch masses present approximately 0.4 dex precision, letting us conclude that our novel technique delivers black hole masses with only mildly lower precision than single-epoch spectroscopy. Conclusions: The J-PAS survey will soon start observing thousands of square degrees without any source preselection other than the photometric depth in the detection band, and thus single-epoch photometry has the potential to provide details on the physical properties of quasar populations that do not satisfy the preselection criteria of previous spectroscopic surveys.

Context. A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection. Aims: We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis. Methods: We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range ~8 km to ~190 km, corresponding to pressure levels from 9 µbar down to a few nanobars. Results: (i) A pressure of 1.18 ± 0.03 µbar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 µbar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude. Light curves are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/659/A136

Context. The Javalambre Photometric Local Universe Survey (J-PLUS) has obtained precise photometry in 12 specially designed filters for large numbers of Galactic stars. Deriving their precise stellar atmospheric parameters and individual elemental abundances is crucial for studies of Galactic structure and the assembly history and chemical evolution of our Galaxy. Aims: Our goal is to estimate not only stellar parameters (effective temperature, Teff, surface gravity, log g, and metallicity, [Fe/H]), but also [α/Fe] and four elemental abundances ([C/Fe], [N/Fe], [Mg/Fe], and [Ca/Fe]) using data from the first data release (DR1) of J-PLUS. Methods: By combining recalibrated photometric data from J-PLUS DR1, Gaia DR2, and spectroscopic labels from the Large sky Area Multi-Object fiber Spectroscopic Telescope, we designed and trained a set of cost-sensitive neural networks, the CSNet, to learn the nonlinear mapping from stellar colours to their labels. Special attention was paid to the poorly populated regions of the label space by giving different weights according to their density distribution. Results: We achieved precisions of δ Teff ∼ 55 K, δlog g ∼ 0.15 dex, and δ [Fe/H] ∼ 0.07 dex, respectively, over a wide range of temperatures, surface gravities, and metallicities. The uncertainties of the abundance estimates for [α/Fe] and the four individual elements are in the 0.04-0.08 dex range. We compare our parameter and abundance estimates with those from other spectroscopic catalogs such as the Apache Point Observatory for Galactic Evolution Experiment and the Galactic Archaeology with High Efficiency and Resolution Multi-Element Spectrograph and find an overall good agreement. Conclusions: Our results demonstrate the potential of well-designed, high-quality photometric data for determinations of stellar parameters as well as individual elemental abundances. Applying the method to J-PLUS DR1, we obtained the aforementioned parameters for about two million stars, providing an outstanding dataset for chemo-dynamic analyses of the Milky Way. The catalog of the estimated parameters is publicly accessible. A copy of the catalog is available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/659/A181

Aims: We estimated the spectral evolution of white dwarfs with effective temperature using the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), which provides 12 photometric optical passbands over 2176 deg2. Methods: We analyzed 5926 white dwarfs with r ≤ 19.5 mag in common between a white dwarf catalog defined from Gaia EDR3 and J-PLUS DR2. We performed a Bayesian analysis by comparing the observed J-PLUS photometry with theoretical models of hydrogen- and helium-dominated atmospheres. We estimated the probability distribution functions for effective temperature (Teff), surface gravity, parallax, and composition; and the probability of having a H-dominated atmosphere (pH) for each source. We applied a prior in parallax, using Gaia EDR3 measurements as a reference, and derived a self-consistent prior for the atmospheric composition as a function of Teff. Results: We described the fraction of white dwarfs with a He-dominated atmosphere (fHe) with a linear function of the effective temperature at 5000 < Teff < 30 000 K. We find fHe = 0.24 ± 0.01 at Teff = 10 000 K, a change rate along the cooling sequence of 0.14 ± 0.02 per 10 kK, and a minimum He-dominated fraction of 0.08 ± 0.02 at the high-temperature end. We tested the obtained pH by comparison with spectroscopic classifications, finding that it is reliable. We estimated the mass distribution for the 351 sources with distance d < 100 pc, mass M > 0.45 M⊙, and Teff > 6000 K. The result for H-dominated white dwarfs agrees with previous studies, with a dominant M = 0.59 M⊙ peak and the presence of an excess at M ∼ 0.8 M⊙. This high-mass excess is absent in the He-dominated distribution, which presents a single peak. Conclusions: The J-PLUS optical data provide a reliable statistical classification of white dwarfs into H- and He-dominated atmospheres. We find a 21 ± 3% increase in the fraction of He-dominated white dwarfs from Teff = 20 000 K to Teff = 5000 K. The catalog with the atmospheric parameters and composition of the analyzed white dwarfs is available in electronic form both on the jplus.WhiteDwarf table at the J-PLUS database and at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/658/A79

Context. We explore the stellar content of the Javalambre Photometric Local Universe Survey (J-PLUS) Data Release 2 and show its potential for identifying low-metallicity stars using the Stellar Parameters Estimation based on Ensemble Methods (SPEEM) pipeline. Aims: SPEEM is a tool used to provide determinations of atmospheric parameters for stars and separate stellar sources from quasars based on the unique J-PLUS photometric system. The adoption of adequate selection criteria allows for the identification of metal-poor star candidates that are suitable for spectroscopic follow-up investigations. Methods: SPEEM consists of a series of machine-learning models that use a training sample observed by both J-PLUS and the SEGUE spectroscopic survey. The training sample has temperatures, Teff, between 4800 K and 9000 K, values of log g between 1.0 and 4.5, as well as −3.1 < [Fe/H] < +0.5. The performance of the pipeline was tested with a sample of stars observed by the LAMOST survey within the same parameter range. Results: The average differences between the parameters of a sample of stars observed with SEGUE and J-PLUS, obtained with the SEGUE Stellar Parameter Pipeline and SPEEM, respectively, are ΔTeff ~ 41 K, Δlog g ~ 0.11 dex, and Δ[Fe/H] ~ 0.09 dex. We define a sample of 177 stars that have been identified as new candidates with [Fe/H] < −2.5, with 11 of them having been observed with the ISIS spectrograph at the William Herschel Telescope. The spectroscopic analysis confirms that 64% of stars have [Fe/H] < −2.5, including one new star with [Fe/H] < −3.0. Conclusions: Using SPEEM in combination with the J-PLUS filter system has demonstrated their potential in estimating the stellar atmospheric parameters (Teff, log g, and [Fe/H]). The spectroscopic validation of the candidates shows that SPEEM yields a success rate of 64% on the identification of very metal-poor star candidates with [Fe/H] < −2.5.

This paper presents time-series observations and analysis of broadband night sky airglow intensity 4 September 2018 through 30 April 2020. Data were obtained at 5 sites spanning more than 8500 km during the historically deep minimum of Solar Cycle 24 into the beginning of Solar Cycle 25. New time-series observations indicate previously unrecognized significant sources of broadband night sky brightness variations, not involving corresponding changes in the Sun's 10.7 cm solar flux, occur during deep solar minimum. New data show; (1) Even during a deep solar minimum the natural night sky is rarely, if ever, constant in brightness. Changes with time-scales of minutes, hours, days, and months are observed. (2) Semi-annual night sky brightness variations are coincident with changes in the orientation of Earth's magnetic field relative to the interplanetary magnetic field. (3) Solar wind plasma streams from solar coronal holes arriving at Earth's bow shock nose are coincident with major night sky brightness increase events. (4) Sites more than 8500 km along the Earth's surface experience nights in common with either very bright or very faint night sky airglow emissions. The reason for this observational fact remains an open question. (5) It is plausible, terrestrial night airglow and geomagnetic indices have similar responses to the solar energy input into Earth's magnetosphere. Our empirical results contribute to a quantitative basis for understanding and predicting broadband night sky brightness variations. They are applicable in astronomical, planetary science, space weather, light pollution, biological, and recreational studies.

Understanding the origins of small-scale flats of CCDs and their wavelength-dependent variations plays an important role in high-precision photometric, astrometric, and shape measurements of astronomical objects. Based on the unique flat data of 47 narrowband filters provided by JPAS-Pathfinder, we analyze the variations of small-scale flats as a function of wavelength. We find moderate variations (from about 1.0% at 390 nm to 0.3% at 890 nm) of small-scale flats among different filters, increasing toward shorter wavelengths. Small-scale flats of two filters close in central wavelengths are strongly correlated. We then use a simple physical model to reproduce the observed variations to a precision of about ±0.14% by considering the variations of charge collection efficiencies, effective areas, and thicknesses between CCD pixels. We find that the wavelength-dependent variations of the small-scale flats of the JPAS-Pathfinder camera originate from inhomogeneities of the quantum efficiency (particularly charge collection efficiency), as well as the effective area and thickness of CCD pixels. The former dominates the variations in short wavelengths, while the latter two dominate at longer wavelengths. The effects on proper flat-fielding, as well as on photometric/flux calibrations for photometric/slitless spectroscopic surveys, are discussed, particularly in blue filters/wavelengths. We also find that different model parameters are sensitive to flats of different wavelengths, depending on the relations between the electron absorption depth, photon absorption length, and CCD thickness. In order to model the wavelength-dependent variations of small-scale flats, a small number (around 10) of small-scale flats with well-selected wavelengths are sufficient to reconstruct small-scale flats in other wavelengths.

Context. The Javalambre Photometric Local Universe Survey (J-PLUS) is an observational campaign that aims to obtain photometry in 12 ultraviolet-visible filters (0.3−1 μm) over ∼8500 deg2 of the sky observable from Javalambre (Teruel, Spain). Due to its characteristics and observation strategy, this survey will allow a great number of Solar System small bodies to be analyzed, and with improved spectrophotometric resolution with respect to previous large-area photometric surveys in optical wavelengths. Aims: The main goal of the present work is to present the first catalog of magnitudes and colors of minor bodies of the Solar System compiled using the first data release (DR1) of the J-PLUS observational campaign: the Moving Objects Observed from Javalambre (MOOJa) catalog. Methods: Using the compiled photometric data we obtained very-low-resolution reflectance (photo)spectra of the asteroids. We first used a σ-clipping algorithm in order to remove outliers and clean the data. We then devised a method to select the optimal solar colors in the J-PLUS photometric system. These solar colors were computed using two different approaches: on one hand, we used different spectra of the Sun convolved with the filter transmissions of the J-PLUS system, and on the other, we selected a group of solar-type stars in the J-PLUS DR1 according to their computed stellar parameters. Finally, we used the solar colors to obtain the reflectance spectra of the asteroids. Results: We present photometric data in the J-PLUS filters for a total of 3122 minor bodies (3666 before outlier removal), and we discuss the main issues with the data, as well as some guidelines to solve them. MOOJa catalog of colors and magnitudes are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/655/A47

MiniJPAS is a ∼1 deg2 imaging survey of the AEGIS field in 60 bands, performed to demonstrate the scientific potential of the upcoming Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS). Full coverage of the 3800-9100 Å range with 54 narrow-band filters, in combination with 6 optical broad-band filters, allows for extremely accurate photometric redshifts (photo-z), which, applied over areas of thousands of square degrees, will enable new applications of the photo-z technique, such as measurement of baryonic acoustic oscillations. In this paper we describe the method we used to obtain the photo-z that is included in the publicly available miniJPAS catalogue, and characterise the photo-z performance. We built photo-spectra with 100 Å resolution based on forced-aperture photometry corrected for point spread function. Systematic offsets in the photometry were corrected by applying magnitude shifts obtained through iterative fitting with stellar population synthesis models. We computed photo-z with a customised version of LEPHARE, using a set of templates that is optimised for the J-PAS filter-set. We analysed the accuracy of miniJPAS photo-z and their dependence on multiple quantities using a subsample of 5266 galaxies with spectroscopic redshifts from SDSS and DEEP, which we find to be representative of the whole r < 23 miniJPAS sample. Formal 1σ uncertainties for the photo-z that are calculated with the Δχ2 method underestimate the actual redshift errors. The odds parameter has a stronger correlation with |Δz| and accurately reproduces the probability of a redshift outlier (|Δz| > 0.03), regardless of the magnitude, redshift, or spectral type of the sources. We show that the two main summary statistics characterising the photo-z accuracy for a population of galaxies (σNMAD and η) can be predicted by the distribution of odds in this population, and we use this to estimate the statistics for the whole miniJPAS sample. At r < 23, there are ∼17 500 galaxies per deg2 with valid photo-z estimates, ∼4200 of which are expected to have |Δz| < 0.003. The typical error is σNMAD = 0.013 with an outlier rate η = 0.39. The target photo-z accuracy σNMAD = 0.003 is achieved for odds > 0.82 with η = 0.05, at the cost of decreasing the density of selected galaxies to n ∼ 5200 deg−2 (∼2600 of which have |Δz| < 0.003).

We estimated the spectral evolution of white dwarfs with effective temperature using the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), that provides twelve photometric optical passbands over 2176 deg2. We analysed 5926 white dwarfs with r <= 19.5 mag in common between a white dwarf catalog defined from Gaia EDR3 and J-PLUS DR2. We performed a Bayesian analysis by comparing the observed J-PLUS photometry with theoretical models of hydrogen (H) and helium (He) dominated atmospheres. We estimated the PDF for effective temperature (Teff), surface gravity, parallax, and spectral type; and the probability of having a H-dominated atmosphere (pH) for each source. We applied a prior in parallax, using Gaia EDR3 measurements as reference, and derived a self-consistent prior for the atmospheric composition as a function of Teff. We described the fraction of He-dominated atmosphere white dwarfs (fHe) with a linear function of Teff at 5000 < Teff < 30000 K. We found fHe = 0.24 +- 0.01 at Teff = 10000 K, a change rate along the cooling sequence of 0.14 +- 0.02 per 10 kK, and a minimum He-dominated fraction of 0.08 +- 0.02 at the high-temperature end. We tested the obtained pH by comparison with spectroscopic classifications, finding that it is reliable. We estimated the mass distribution for the 351 sources with distance d < 100 pc, mass M > 0.45 Msun, and Teff > 6000 K. The result for H-dominated white dwarfs agrees with previous work, with a dominant M = 0.59 Msun peak and the presence of an excess at M ~ 0.8 Msun. This high-mass excess is absent in the He-dominated distribution, which presents a single peak. The J-PLUS optical data provides a reliable statistical classification of white dwarfs into H- and He-dominated atmospheres. We find a 21 +- 3 % increase in the fraction of He-dominated white dwarfs from Teff = 20000 K to Teff = 5000 K.

Extragalactic globular clusters (GCs) are key objects for studying the formation and evolution of galaxies. The arrival of wide-field surveys such as the Javalambre Photometric Local Universe Survey (J-PLUS) offers new possibilities for the study of GCs. Nevertheless, GCs are not detected a priori by the data reduction pipeline of J-PLUS and, due to its pixel scale, the standard techniques of GCs detection are challenged. To fill this gap, we develop a semi-automatic pipeline to detect GCs in J-PLUS that can also be adapted to similar surveys. As a case study, we use data from the S0 galaxy NGC 1023 and we also study the stellar population content of GC candidates in the galaxy. To detect GCs, our methodology is based on Source Extractor and does not require a previous filtering or modelling of the host galaxy. We study colors and perform spectral energy distribution (SED) analysis on our final GC candidate catalog to obtain stellar population parameters. In NGC 1023, GCFinder identifies 523 GC candidates. We observe evidence of color bimodality in a few broad-band colors but not on narrow-band colors. The SED analysis reveals a clear metallicity bimodality and we observe that narrow-band filters are very useful to constrain metallicities. We also identified a broad age-metallicity relation as well as a wide metallicity distribution that are evidence that NGC 1023 experienced accretion events in the past. It is the first time this kind of study is performed with J-PLUS data. By detecting GC candidates in wide-field images without modeling the light of the galaxy, GCFinder becomes considerably faster, at a marginal loss of centrally-located GC candidates of about 7 percent. As GCFinder is entirely based on Source Extractor, it could be easily incorporated into automated software handling wide-field surveys.

Aims: We present the photometric calibration of the twelve optical passbands for the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), comprising 1088 pointings of two square degrees, and study the systematic impact of metallicity on the stellar locus technique. Methods: The [Fe/H] metallicity from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) for 146 184 high-quality calibration stars, defined with signal-to-noise ratio larger than ten in J-PLUS passbands and larger than three in Gaia parallax, was used to compute the metallicity-dependent stellar locus (ZSL). The initial homogenization of J-PLUS photometry, performed with a unique stellar locus, was refined by including the metallicity effect in colors via the ZSL. Results: The variation of the average metallicity along the Milky Way produces a systematic offset in J-PLUS calibration. This effect is well above 1% for the bluer passbands and amounts 0.07, 0.07, 0.05, 0.03, and 0.02 mag in u, J0378, J0395, J0410, and J0430, respectively. We modeled this effect with the Milky Way location of the J-PLUS pointing, also providing an updated calibration for those observations without LAMOST information. The estimated accuracy in the calibration after including the metallicity effect is at 1% for the bluer J-PLUS passbands and below for the rest. Conclusions: Photometric calibration with the stellar locus technique is prone to significant systematic bias in the Milky Way for passbands bluer than λ = 4500 Å. The calibration method for J-PLUS DR2 reaches 1-2% precision and 1% accuracy for 12 optical filters within an area of 2176 square degrees.

We observed the Fermi-LAT position (Di Lalla et al., GCN #30961) of the bright Fermi GRB 211023A (Fermi detection: Fermi GBM Team, GCN #30958; Lesage et al., GCN #30965; AGILE detection: Ursi et al., GCN #30969) with the JAST/T80 telescope of OAJ, Teruel, Spain. We obtained 3 x 300 s images each in g', r', and i' under good conditions. At the position of the MASTER afterglow candidate (Zhirkov et al., GCN #30977), we detect a bright source which is not visible in Pan-STARRS archival imaging. Against three Pan-STARRS comparison stars, we measure r' = 18.03 +/- 0.02 mag (AB mag) at 0.5704 d after the GRB. We note this is an exceedingly bright afterglow, just slightly fainter at similar times than those of GRBs 130427A and 181201A. We also note a resemblance in prompt emission shape, fluence (S. Poolakkil, priv. comm.), and peak energy to the famous GRB 030329. Spectroscopic observations and further follow-up are encouraged.

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2 deg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3 deg2 field-of-view and plate scale of 0.23 arcsec pixel−1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a ∼1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHM ∼ 145 Å) and two broader filters extending to the UV and the near-infrared, complemented by the u, g, r, i SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magAB ≃ 22−23.5 in the 54 narrow band filters and up to 24 in the broader filters (5σ in a 3″ aperture). The miniJPAS primary catalog contains more than 64 000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at r = 23.6 (r = 22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to r = 22.5, and a precision of ≤0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to z ∼ 0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to z > 2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude.

There is a growing interest in the automated characterization of open clusters using data from the Gaia mission. This work evidences the importance of choosing an appropriate sampling radius (the radius of the circular region around the cluster used to extract the data) and the usefulness of additional multiband photometry in order to achieve accurate results. We address this issue using as a case study the cluster Alessi-Teutsch 9. The optimal sampling is determined by counting the number of assigned members at different sampling radii. By using this strategy with data from Gaia EDR3 and with observed photometry in 12 bands spanning the optical range from 3000 to 10000 Å, approximately, we are able to obtain reliable members and to determine the properties of the cluster. The spatial distribution of stars show a two-component structure with a central core of radius ∼12 −13 arcmin and an outer halo extending out to 35 arcmin. With the derived cluster distance (654 pc) we obtain that the number density of stars is ≃0.06 star/pc3, making Alessi-Teutsch 9 one of the less dense known open clusters. The short relaxation time reveals that it is a dynamically relaxed and gravitationally bound system.

The GALANTE optical photometric survey is observing the northern Galactic plane and some adjacent regions using seven narrow- and intermediate-filters, covering a total of 1618 deg2. The survey has been designed with multiple exposure times and at least two different air masses per field to maximize its photometric dynamic range, comparable to that of Gaia, and ensure the accuracy of its photometric calibration. The goal is to reach at least 1 per cent accuracy and precision in the seven bands for all stars brighter than AB magnitude 17 while detecting fainter stars with lower values of the signal-to-noise ratio. The main purposes of GALANTE are the identification and study of extinguished O+B+WR stars, the derivation of their extinction characteristics, and the cataloguing of F and G stars in the solar neighbourhood. Its data will be also used for a variety of other stellar studies and to generate a high-resolution continuum-free map of the Hα emission in the Galactic plane. We describe the techniques and the pipeline that are being used to process the data, including the basis of an innovative calibration system based on Gaia DR2 and 2MASS photometry.

The next generation of galaxy surveys will allow us to test some fundamental aspects of the standard cosmological model, including the assumption of a minimal coupling between the components of the dark sector. In this paper, we present the Javalambre Physics of the Accelerated Universe Astrophysical Survey (J-PAS) forecasts on a class of unified models where cold dark matter interacts with a vacuum energy, considering future observations of baryon acoustic oscillations, redshift-space distortions, and the matter power spectrum. After providing a general framework to study the background and linear perturbations, we focus on a concrete interacting model without momentum exchange by taking into account the contribution of baryons. We compare the J-PAS results with those expected for DESI and Euclid surveys and show that J-PAS is competitive to them, especially at low redshifts. Indeed, the predicted errors for the interaction parameter, which measures the departure from a ΛCDM model, can be comparable to the actual errors derived from the current data of cosmic microwave background temperature anisotropies.

Understanding the origins of small-scale flats of CCDs and their wavelength-dependent variations plays an important role in high-precision photometric, astrometric, and shape measurements of astronomical objects. Based on the unique flat data of 47 narrow-band filters provided by JPAS-{\it Pathfinder}, we analyze the variations of small-scale flats as a function of wavelength. We find moderate variations (from about 1.0%1.0% at 390 nm to 0.3%0.3% at 890 nm) of small-scale flats among different filters, increasing towards shorter wavelengths. Small-scale flats of two filters close in central wavelengths are strongly correlated. We then use a simple physical model to reproduce the observed variations to a precision of about ±0.14%±0.14% , by considering the variations of charge collection efficiencies, effective areas and thicknesses between CCD pixels. We find that the wavelength-dependent variations of small-scale flats of the JPAS-{\it Pathfinder} camera originate from inhomogeneities of the quantum efficiency (particularly charge collection efficiency) as well as the effective area and thickness of CCD pixels. The former dominates the variations in short wavelengths while the latter two dominate at longer wavelengths. The effects on proper flat-fielding as well as on photometric/flux calibrations for photometric/slit-less spectroscopic surveys are discussed, particularly in blue filters/wavelengths. We also find that different model parameters are sensitive to flats of different wavelengths, depending on the relations between the electron absorption depth, the photon absorption length and the CCD thickness. In order to model the wavelength-dependent variations of small-scale flats, a small number (around ten) of small-scale flats with well-selected wavelengths are sufficient to reconstruct small-scale flats in other wavelengths.

We observed the afterglow of GRB 210704A (BALROG localization: Kunzweiler et al., GCN #30369; Fermi/LAT detection: Berretta et al., GCN #30375; Fermi/GBM detection: Malacaria & Meegan, GCN #30382; AGILE/MCAL detection: Ursi et al., GCN #30372; AstroSat/CZTI detection: Prasad et al., GCN #30378; Konus-Wind detection: Ridnaia et al., GCN #30388; Swift/XRT afterglow detection: D'Ai et al., GCN #30379) with the T80 0.8m telescope at the Observatorio de Javalambre (Teruel, Spain). Observations consisted of 3 x 300 s in z', i', g' r' each, at midtimes 1.081, 1.093, 1.104, and 1.116 days after the GRB, respectively. The afterglow (Kim et al., GCN #30384, D'Avanzo et al., GCN #30385, Kann et al., GCN #30391, de Ugarte Postigo et al., GCN #30392) is well-detected in g'r', faintly in i' and not in z'. Against four Pan-STARRS field stars, we measure (AB magnitudes): g' = 22.42 +/- 0.11 mag; r' = 22.17 +/- 0.10 mag; i' = 22.08 +/- 0.23 mag; z' > 21.5 mag at the above-mentioned mid-times.

Context. In modern astronomy, machine learning has proved to be efficient and effective to mine the big data from the newest telescopes. Spectral surveys enable us to characterize millions of objects, while long exposure time observations and wide surveys constrain their strides from millions to billions. Aims. In this study, we construct a supervised machine learning algorithm, to classify the objects in the Javalambre Photometric Local Universe Survey first data release (J-PLUS DR1). Methods. The sample set is featured with 12-waveband photometry, and magnitudes are labeled with spectrum-based catalogs, including Sloan Digital Sky Survey spectroscopic data, Large Sky Area Multi-Object Fiber Spectroscopic Telescope, and VERONCAT - Veron Catalog of Quasars & AGN. The performance of the classifier is presented with applications of blind test validations based on RAdial Velocity Extension, Kepler Input Catalog, 2 MASS Redshift Survey, and the UV-bright Quasar Survey. A new algorithm is applied to constrain the extrapolation that could decrease accuracies for many machine learning classifiers. Results. The accuracies of the classifier are 96.5% in blind test and 97.0% in training cross validation. The F1-scores for each class are presented to show the precision of the classifier. We also discuss different methods to constrain the potential extrapolation.

Aims: Our goal is to estimate the star formation main sequence (SFMS) and the star formation rate density (SFRD) at z ≤ 0.017 (d ≲ 75 Mpc) using the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, that probes 897.4 deg2 with twelve optical bands. Methods: We extract the Hα emission flux of 805 local galaxies from the J-PLUS filter J0660, being the continuum level estimated with the other eleven J-PLUS bands, and the dust attenuation and nitrogen contamination corrected with empirical relations. Stellar masses (M⋆), Hα luminosities (LHα), and star formation rates (SFRs) were estimated by accounting for parameters covariances. Our sample comprises 689 blue galaxies and 67 red galaxies, classified in the (u − g) vs. (g − z) color-color diagram, plus 49 AGN. Results: The SFMS is explored at log M⋆ ≳ 8 and it is clearly defined by the blue galaxies, with the red galaxies located below them. The SFMS is described as log SFR = 0.83log M⋆ − 8.44. We find a good agreement with previous estimations of the SFMS, especially those based on integral field spectroscopy. The Hα luminosity function of the AGN-free sample is well described by a Schechter function with log LHα∗ = 41.34, log ϕ* = −2.43, and α = −1.25. Our measurements provide a lower characteristic luminosity than several previous studies in the literature. Conclusions: The derived star formation rate density at d ≲ 75 Mpc is log ρSFR = −2.10 ± 0.11, with red galaxies accounting for 15% of the SFRD. Our value is lower than previous estimations at similar redshift, and provides a local reference for evolutionary studies regarding the star formation history of the Universe.

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start imaging thousands of square degrees of the northern sky with its unique set of 56 filters (spectral resolution of R ∼ 60). Before the arrival of the final instrument, we observed 1 deg2 on the AEGIS field with an interim camera with all the J-PAS filters. Taking advantage of these data, dubbed miniJPAS, we aim at proving the scientific potential of the J-PAS to derive the stellar population properties of galaxies via fitting codes for spectral energy distributions (SEDs), with the ultimate goal of performing galaxy evolution studies across cosmic time. One parametric (BaySeAGal) and three non-parametric (MUFFIT, AlStar, and TGASPEX) SED-fitting codes are used to constrain the stellar mass, age, metallicity, extinction, and rest-frame and dust-corrected (u − r) colours of a complete flux-limited sample (rSDSS ≤ 22.5 AB) of miniJPAS galaxies that extends up to z = 1. We generally find consistent results on the galaxy properties derived from the different codes, independently of the galaxy spectral type or redshift; this is remarkable considering that 25% of the J-spectra have signal-to-noise ratios (S/N) ∼3. For galaxies with S/N ≥ 10, we estimate that the J-PAS photometric system will allow us to derive the stellar population properties of rest-frame (u − r) colour, stellar mass, extinction, and mass-weighted age with a precision of 0.04 ± 0.02 mag, 0.07 ± 0.03 dex, 0.2 ± 0.09 mag, and 0.16 ± 0.07 dex, respectively. This precision is equivalent to that obtained with spectroscopic surveys of similar S/N. By using the dust-corrected (u − r) colour-mass diagram, a powerful proxy for characterizing galaxy populations, we find: (i) that the fraction of red and blue galaxies evolves with cosmic time, with red galaxies being ∼38% and ∼18% of the whole population at z = 0.1 and z = 0.5, respectively, and (ii) consistent results between codes for the average intrinsic (u − r) colour, stellar mass, age, and stellar metallicity of blue and red galaxies and their evolution up to z = 1. At all redshifts, the more massive galaxies belong to the red sequence, and these galaxies are typically older and more metal-rich than their counterparts in the blue cloud. Our results confirm that with J-PAS data we will be able to analyse large samples of galaxies up to z ∼ 1, with galaxy stellar masses above log(M⋆/M⊙)∼8.9, 9.5, and 9.9 at z = 0.3, 0.5, and 0.7, respectively. The star formation history of a complete sub-sample of galaxies selected at z ∼ 0.1 with log(M⋆/M⊙) > 8.3 constrains the cosmic evolution of the star formation rate density up to z ∼ 3, in good agreement with results from cosmological surveys.

We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (mV = 14.0 mag) by the centaur 2002 GZ32 for 2017 May 20. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of images were obtained with 29 telescopes throughout Europe and from six of them (five in Spain and one in Greece) we detected the occultation. This is the fourth centaur, besides Chariklo, Chiron, and Bienor, for which a multichord stellar occultation is reported. By means of an elliptical fit to the occultation chords, we obtained the limb of 2002 GZ32 during the occultation, resulting in an ellipse with axes of 305 ± 17 km × 146 ± 8 km. From this limb, thanks to a rotational light curve obtained shortly after the occultation, we derived the geometric albedo of 2002 GZ32 (pV = 0.043 ± 0.007) and a 3D ellipsoidal shape with axes 366 km × 306 km × 120 km. This shape is not fully consistent with a homogeneous body in hydrostatic equilibrium for the known rotation period of 2002 GZ32. The size (albedo) obtained from the occultation is respectively smaller (greater) than that derived from the radiometric technique but compatible within error bars. No rings or debris around 2002 GZ32 were detected from the occultation, but narrow and thin rings cannot be discarded.

In the years to come, the Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) will observe 8000 deg2 of the northern sky with 56 photometric bands. J-PAS is ideal for the detection of nebular emission objects. This paper presents a new method based on artificial neural networks (ANNs) that is aimed at measuring and detecting emission lines in galaxies up to z = 0.35. These lines are essential diagnostics for understanding the evolution of galaxies through cosmic time. We trained and tested ANNs with synthetic J-PAS photometry from CALIFA, MaNGA, and SDSS spectra. To this aim, we carried out two tasks. First, we clustered galaxies in two groups according to the values of the equivalent width (EW) of Hα, Hβ, [N II], and [O III] lines measured in the spectra. Then we trained an ANN to assign a group to each galaxy. We were able to classify them with the uncertainties typical of the photometric redshift measurable in J-PAS. Second, we utilized another ANN to determine the values of those EWs. Subsequently, we obtained the [N II]/Hα, [O III]/Hβ, and O 3N 2 ratios, recovering the BPT diagram ([O III]/Hβ versus [N II]/Hα). We studied the performance of the ANN in two training samples: one is only composed of synthetic J-PAS photo-spectra (J-spectra) from MaNGA and CALIFA (CALMa set) and the other one is composed of SDSS galaxies. We were able to fully reproduce the main sequence of star-forming galaxies from the determination of the EWs. With the CALMa training set, we reached a precision of 0.092 and 0.078 dex for the [N II]/Hα and [O III]/Hβ ratios in the SDSS testing sample. Nevertheless, we find an underestimation of those ratios at high values in galaxies hosting an active galactic nuclei. We also show the importance of the dataset used for both training and testing the model. Such ANNs are extremely useful for overcoming the limitations previously expected concerning the detection and measurements of the emission lines in such surveys as J-PAS. Furthermore, we show the capability of the method to measure a EW of 10 Å in Hα, Hβ, [N II] and [O III] lines with a signal-to-noise ratio (S/N) of 5, 1.5, 3.5, and 10, respectively, in the photometry. Finally, we compare the properties of emission lines in galaxies observed with miniJPAS and SDSS. Despite the limitation of such a comparison, we find a remarkable correlation in their EWs.

We have detected a broad interstellar absorption band centred close to 7700 Å and with a FWHM of 176.6±3.9 Å. This is the first such absorption band detected in the optical range and is significantly wider than the numerous diffuse interstellar bands (DIBs). It remained undiscovered until now because it is partially hidden behind the A telluric band produced by O2. The band was discovered using STIS@HST spectra and later detected in a large sample of stars of diverse type (OB stars, BA supergiants, red giants) using further STIS and ground-based spectroscopy. The EW of the band is measured and compared with our extinction and K I λλ7667.021,7701.093 measurements for the same sample. The carrier is ubiquitous in the diffuse and translucent Galactic ISM but is depleted in the environment around OB stars. In particular, it appears to be absent or nearly so in sightlines rich in molecular carbon. This behaviour is similar to that of the σ-type DIBs, which originate in the low/intermediate-density UV-exposed ISM but are depleted in the high-density UV-shielded molecular clouds. We also present an update on our previous work on the relationship between E(4405 - 5495) and R5495 and incorporate our results into a general model of the ISM.

Context. Future astrophysical surveys such as J-PAS will produce very large datasets, the so-called "big data", which will require the deployment of accurate and efficient machine-learning (ML) methods. In this work, we analyze the miniJPAS survey, which observed about ∼1 deg2 of the AEGIS field with 56 narrow-band filters and 4 ugri broad-band filters. The miniJPAS primary catalog contains approximately 64 000 objects in the r detection band (magAB ≲ 24), with forced-photometry in all other filters. Aims: We discuss the classification of miniJPAS sources into extended (galaxies) and point-like (e.g., stars) objects, which is a step required for the subsequent scientific analyses. We aim at developing an ML classifier that is complementary to traditional tools that are based on explicit modeling. In particular, our goal is to release a value-added catalog with our best classification. Methods: In order to train and test our classifiers, we cross-matched the miniJPAS dataset with SDSS and HSC-SSP data, whose classification is trustworthy within the intervals 15 ≤ r ≤ 20 and 18.5 ≤ r ≤ 23.5, respectively. We trained and tested six different ML algorithms on the two cross-matched catalogs: K-nearest neighbors, decision trees, random forest (RF), artificial neural networks, extremely randomized trees (ERT), and an ensemble classifier. This last is a hybrid algorithm that combines artificial neural networks and RF with the J-PAS stellar and galactic loci classifier. As input for the ML algorithms we used the magnitudes from the 60 filters together with their errors, with and without the morphological parameters. We also used the mean point spread function in the r detection band for each pointing. Results: We find that the RF and ERT algorithms perform best in all scenarios. When the full magnitude range of 15 ≤ r ≤ 23.5 is analyzed, we find an area under the curve AUC = 0.957 with RF when photometric information alone is used, and AUC = 0.986 with ERT when photometric and morphological information is used together. When morphological parameters are used, the full width at half maximum is the most important feature. When photometric information is used alone, we observe that broad bands are not necessarily more important than narrow bands, and errors (the width of the distribution) are as important as the measurements (central value of the distribution). In other words, it is apparently important to fully characterize the measurement. Conclusions: ML algorithms can compete with traditional star and galaxy classifiers; they outperform the latter at fainter magnitudes (r ≳ 21). We use our best classifiers, with and without morphology, in order to produce a value-added catalog. Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/645/A87 The catalog is available at http://j-pas.org/datareleases via the ADQL table minijpas.StarGalClass. The ML models are available at http://github.com/J-PAS-collaboration/StarGalClass-MachineLearning.

Wide field photometric surveys aim at observing large areas of sky in various filters. Yet, almost all surveys use constant exposure times, regardless of the quality of the images or the level of background, mostly due to the moon, which may result in a lack of homogeneity in the data sets. In the J-PLUS survey,1 modulating the exposure time with the sky background has resulted not only in an improved homogeneity of the data but also in a significant improvement of the efficiency of the survey execution. In this paper, we show the effect on J-PAS and J-PLUS of using fixed exposure times, regardless of the Moon background, and we describe the system to estimate this background reliably and provide a significant improvement, not only in the quality of the observations, but also in the survey speed.

IAU Designation: SN 2020admb Discoverer internal name: JVAR20a Coordinates (J2000): RA = 08:32:25.992 (128.1083) DEC = +56:27:53.64 (56.4649) Discovery date: 2020-12-22 03:54:32.000 (JD=2459205.6628704) Potential host galaxy: MCG+09-14-052 Host redshift: 0.044 Remarks: J-VAR is an Open Time project running with JAST80 at the Observatorio Astrofísico de Javalambre, Teruel (Spain). J-VAR is a variability oriented project observing with a subset of the J-PLUS (Cenarro et al. 2019) filter system: J0395 (narrow), g, J0515 (narrow), r, J0660 (narrow), i and J0861 (intermediate). The spectroscopic redshift of the host galaxy has been taken from SDSS.

We present the photometric determination of the bright end of the Lyα luminosity function (LF; at LLyα ≳ 1043.3 erg s-1) within four redshift windows (∆ z < 0.16) in the interval 2.2​ ≲ ​z​ ≲ ​3.3. Our work is based on the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, which provides multiple narrow-band measurements over ∼1000 deg2, with limiting magnitude r​ ∼ ​22. The analysis of high-z Lyα-emitting sources over such a wide area is unprecedented and allows us to select approximately 14 500 hyper-bright (LLyα > 1043.3 erg s-1) Lyα-emitting candidates. We test our selection with two spectroscopic programs at the GTC telescope, which confirm ∼89% of the targets as line-emitting sources, with ∼64% being genuine z​ ∼ ​2.2 quasars (QSOs). We extend the 2.2​ ≲ ​z​ ≲ ​3.3 Lyα LF for the first time above LLyα ∼ 1044 erg s-1 and down to densities of ∼10-8 Mpc-3. Our results unveil the Schechter exponential decay of the brightest-end of the Lyα LF in great detail, complementing the power-law component of previous determinations at 43.3 ≲ Log10(LLyα/erg s-1) ≲ 44. We measure Φ* = (3.33 ± 0.19)×10-6, Log(L*) = 44.65 ± 0.65, and α = -1.35 ± 0.84 as an average over the probed redshifts. These values are significantly different from the typical Schechter parameters measured for the Lyα LF of high-z star-forming Lyman-α emitters (LAEs). This implies that z​ > ​2 AGNs/QSOs (likely dominant in our samples) are described by a structurally different LF from that used to describe z​ > ​2 star-forming LAEs, namely LQSOs* ~ 100LLAEs* and ΦQSOs* ~ 10-3 ΦLAEs*, with the transition between the two LFs happening at LLyα ∼ 1043.5 erg s-1. This supports the scenario in which Lyα-emitting AGNs/QSOs are the most abundant class of z​ ≳ ​2 Lyα emitters at LLyα ≳ 1043.3 erg s-1. Finally, we suggest that a significant number of these z​ ≳ ​2 AGNs/QSOs (∼60% of our samples) are currently misclassified as stars based on their broad-band colours, but are identified for the first time as high-z line-emitters by our narrow-band-based selection. Catalogs are available in electronic form both on the J-PLUS website at http://https://www.j-plus.es/ancillarydata/dr1_lya_emitting_candidates and at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A149

Relative importance of the features used for the classification of sources into extended (galaxies) and point-like (e.g. stars) objects. Table 2a (first and second columns of Table 2 in the paper) gives the feature importance for the analysis that uses only photometric bands while Table 2b (third and fourth columns of Table 2 in the paper) gives the importance for the analysis that uses also morphological information. The analysis is relative to the crossmatched catalog XMATCH.

The location of large telescopes, generally far from the data processing centers, represents a logistical problem for the supervision of the capture of images. In this work, we carried out a preliminary study of the vibration signature of the T80 telescope at the Javalambre Astrophysical Observatory (JAO). The study analyzed the process of calculating the displacement that occurs because of the vibration in each of the frequencies in the range of interest. We analyzed the problems associated with very low frequencies by means of simulation, finding the most critical vibrations below 20 Hz, since they are the ones that generate greater displacements. The work also relates previous studies based on simulation with the real measurements of the vibration of the telescope taken remotely when it is subjected to different positioning movements (right ascension and/or declination) or when it performs movement actions such as those related to filter trays or mirror cover. The obtained results allow us to design a remote alarm system to detect invalid images (taken with excess vibration).

Cataclysmic Variables (CVs) are binaries in which a white dwarf accretes from a low-mass companion star. CVs are the best-suited laboratories to test our understanding of the evolution of compact, interacting binaries as they are numerous, relatively bright, and both stellar components are structurally simple. Nonetheless, while a large fraction (≃ 40 - 80 %) of the present-day Galactic CV population is expected to be old, highly evolved and to host brown dwarf companions, yet very few of these so-called "period bouncers" have been identified so far. The lack of these systems in the observed Galactic CV population possibly suggests that the physical mechanisms driving CV evolution (such as the common envelope phase, the mechanisms of angular momentum loss and/or the response of the companions to the mass loss) are still not completely understood. The Compact binary HIgh CAdence Survey (CHiCaS) is a high cadence photometric survey performing three hours of uninterrupted time series photometry at one minute cadence over 136 square degrees of sky with JAST/T80Cam. CHiCaS aims to unambiguously identify the predicted large population of period-bounce CVs via detection of binary eclipses, thus providing an observational support for the current evolutionary models of all kind of compact binaries, such as black hole binaries, X-ray transients, double degenerates or SN Ia progenitors. Moreover, CHiCaS will deliver high cadence light curves along with full-colour information for about 2.5 million sources, thus identifying several hundred thousand variable stars, including eclipsing and contact binaries, pulsating and flaring stars, which will provide a significant legacy value.The Compact binary HIgh CAdence Survey (CHiCaS) is a high cadence photometric survey performing three hours of uninterrupted time series photometry at one minute cadence over 136 square degrees of sky with JAST/T80Cam. CHiCaS aims to unambiguously identify the predicted large population of periodbounce CVs via detection of binary eclipses, thus providing an observational support for the current evolutionary models of all kind of compact binaries, such as black hole binaries, X-ray transients, double degenerates or SN Ia progenitors. Moreover, CHiCaS will deliver high cadence lightcurves along with full-colour information for about 2.5 million stars, thus identifying several hundred thousand variable stars, including eclipsing and contact binaries, pulsating and flaring stars, which will provide a significant legacy value.

These four lists contain sources selected as genuine Lyman-alpha emitting candidates by the methodology detailed in the paper. In brief, the J-PLUS narrow-bands J0395, J0410, J0430 and J0515 were used to detect photometric excesses of sources within the DR1 dual-mode (i.e. r-band selected) parent sample. This excess and its significance was estimated by using the method detailed in Vilella-Rojo et al. (2015A&A...580A..47V) and discussed in Logrono-Garcia et al. (2019A&A...622A.180L). Each of the four NBs were used to target Lyman-alpha emission, respectively at redshift z=2.2, z=2.4, z=2.5 and z=3.2. After the first selection based on the NB-excess significance of each source, the resulting lists of objects were cleaned from the presence of known interlopers, namely low-z galaxies, stars and AGN/QSOs outside the redshift intervals probed by the narrow-bands for Lyman-alpha emission. All the above steps are extensively detailed in the paper. The four lists presented here include only the genuine Lyα-emitting candidates used to compute the luminosity functions presented in the paper. These candidates are defined as the sources selected on the basis of their reliable NB excess, which do not present any identification as known low-z interlopers. We stress that genuine candidates include the Lyα-emitting QSOs belonging to the SDSS spectroscopic sample (Paris et al., 2018A&A...613A..51P, Cat. VII/286), whose redshift is compatible to Lyα-emission in the wavelength ranges probed by each narrow-band. See paper for further details about the selection procedures.

GALANTE is an optical (3000-9000 Å) photometric survey with seven intermediate/narrow filters that has been covering the Galactic Plane since 2016 using the Javalambre JAST/T80. The GALANTE photometric system (defined in Lorenzo et al. 2019) is designed to identify the majority of the early-type massive stars within several kpc of the Sun and derive estimations for stellar parameters (Maíz Apellániz & Sota 2008; Maíz Apellániz et al. 2014). The calibration scheme make use of external 2MASS and Gaia (photometric and astrometric) data. As of mid 2020, 21% of the project observations have been completed, resulting in over 300 1.4°x1.4° astronomical fields. The pipeline is functional and here we focus on our test field, Berkeley 59, showing preliminary results. The collaboration will ultimately provide a 7-filter photometric catalog of stars with a precision of several mili-magnitudes.

Tracing metal-poor stars in the halo of the Milky Way can help detecting stellar tidal streams that provide valuable information about the structure and evolution of our Galaxy. The work described in this talk can be considered as a first step in the validation of a novel and efficient photometric method, based on narrow and intermediate band filters, to determine the metallicity of metal-poor stars. The method is based on the use of filters sensitive to the Ca HK and Ca II IRT absorption lines, both closely related to the metal abundancies, and benefits from the advantages of photometry wrt spectroscopy, i.e efficiency and depth. We have obtained such photometry for the globular clusters M3, M5, M13 M15, M92 and Pal5 at the Javalambre Astrophysics Observatory, whose J-PLUS photometric system includes such filters. The observational data have been compared with theoretical predictions obtained with the BaSTI tool and the results show the potentiality of the method to estimate metallicities in a wide range of values.

The study of the white dwarf (WD) population has greatly advance in the last years thanks to the Gaia mission. The parallax data from Gaia DR2 have provided the largest catalogue of WDs up to date, with ∼260,000 high-probability candidates. The physical properties of these WDs can be obtained from broad-band photometry, but the precision can be improved with narrow-band information. In this contribution, we analyse 2300 WDs in common between Gaia and J-PLUS DR1 (1022 squared degrees in 12 photometric bands; j-plus.es) at r < 19.5. We derived Teff, log g and WD type (DA or DB+DC) with a Bayesian fitting method. We find that the J-PLUS photometry improves the WD classification, specially at Teff < 10,000 K, where broad bands are not sensitive enough. Moreover, we demonstrate that the J-PLUS filter J0395 is able to trace Calcium absorption in the WD atmosphere, so J-PLUS can be used to search for new DZ WDs. We will explore these topics with the future J-PLUS DR2, that will cover more than 2000 sq. degrees, and J-PAS, that will provide low-resolution (R~50) photo-spectra for thousands of white dwarfs.

The Javalambre-Physics of the Acclerating Universe Asptrohysical Survey (J-PAS) have just started to scan thousands of square degrees of the northern sky with 54 narrow band filters and the JPCam instrument with the telescope 2.5m of the Javalambre Observatory. Before the JPCam started its operation, we have observed with the Pathfinder camera one square degree on the AEGIS field (along the extended Groth Strip). Thanks to its large field of view and its spectral resolution comparable to the one of a very low resolution spectroscopy, it brings a great opportunity to study the stellar population properties of the galaxies belonging to a cluster. We used the data obtained for the Cluster 1001 to study its properties. In particular, we consider the mass-weighted age, the stellar mass, the extinction (AV), the metallicity and the SFH to find out if the star formation has been quenched in the galaxies of the cluster. We also use the criteria given by Díaz-García et al. (2019) to separate galaxies into red galaxies and blue galaxies. Our results show a fraction of 0.53 for red galaxies and 0.47 for blue galaxies. We find that most of the red galaxies are the closest ones to the main brightest galaxy of the cluster, while most of the blue galaxies draw a line in the sky. Our results show that most of the galaxies present high values for t0 (the time at which the star formation started) and low values of tau for red galaxies. Further works studying the effects of the environment in the galaxy evolution will be carried out for groups and clusters detected in J-PAS.

The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS, see Benítez et al. 2014) is an unprecedented photometric survey planning to observe 8500 deg2 of the sky from the Observatorio Astrofísico de Javalambre (OAJ). Even tough this survey will start this year, there is already a first data release referred as mini-JPAS (Bonoli et al. 2020), which was used by the J-PAS collaboration to perform the first scientific exploitation of the data. In our case, we aimed at determining the stellar population parameters of galaxies (age, metallicity, extinction, stellar mass, luminosities, star formation histories) using this kind of data. All this with the ultimate goal of discarding any kind of biased result from our group's SED-fitting codes and remarking the robustness of J-PAS to explore the stellar content of galaxies since redshift z=1. After running the SED-fitting code MUFFIT (Díaz-García et al. 2015), we found that galaxies exhibit a bimodal distribution of colours in rest-frame colour diagrams, which is tightly related to their stellar content. This bimodality is even more clear after correcting colours for extinction effects, which reveals that extinction is an important parameter to perform a proper spectral-type classification of galaxies: quiescent and star-forming. Our galaxy evolution group has already a collection of tools to properly determine stellar population properties of galaxies from the J-PAS survey and set milestones on the assembly and evolution of the stellar content of galaxies.

GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of 25 telescopes of different sizes, including both photometric and spectroscopic facilities. The network aims to coordinate follow-up observations of gravitational-wave (GW) candidate alerts, especially those with large localization uncertainties, to reduce the delay between the initial detection and the optical confirmation. In this paper, we detail GRANDMA's observational performance during Advanced LIGO/Advanced Virgo Observing Run 3 (O3), focusing on the second part of O3; this includes summary statistics pertaining to coverage and possible astrophysical origin of the candidates. To do so, we quantify our observation efficiency in terms of delay between GW candidate trigger time, observations, and the total coverage. Using an optimized and robust coordination system, GRANDMA followed-up about 90 per cent of the GW candidate alerts, that is 49 out of 56 candidates. This led to coverage of over 9000 deg2 during O3. The delay between the GW candidate trigger and the first observation was below 1.5 h for 50 per cent of the alerts. We did not detect any electromagnetic counterparts to the GW candidates during O3, likely due to the very large localization areas (on average thousands of degrees squares) and relatively large distance of the candidates (above 200 Mpc for 60 per cent of binary neutron star, BNS candidates). We derive constraints on potential kilonova properties for two potential BNS coalescences (GW190425 and S200213t), assuming that the events' locations were imaged.

We observed the LAT position of the bright GRB 200613A (Fermi-LAT detection: Ohno et al. GCN #27931, Fermi GBM detection: Bissaldi & Lesage, GCN #27930) with the T80 0.8m telescope at the Observatorio de Javalambre (Teruel, Spain). Observations consisted of 3 x 300 s in g', 3 x 300 s in r', and 5 x 180 s in i'. At the position of the second reported XRT source, we detect an optical source not seen to several magnitudes deeper in PanSTARRS archival imaging. The source is detected in each frame. The position is RA (J2000) = 10:12:10.08, Dec. (J2000) = 45:54:14.26 with an estimated error of 0".5. There is also a cataloged SDSS source nearby at RA (J2000) = 10:12:10.075, Dec. (J2000) = 45:54:12.88, this may be the host galaxy of the GRB, though we note nothing is detected here in the PanSTARRS image. Further analysis is in progress. Spectroscopic observations are encouraged.

The source reported in Kann et al., GCN #27935, lies at coordinates: RA (J2000) = 10:12:10.08 Dec. (J2000) = 45:45:14.26 and is therefore coincident with the XRT afterglow (Kennea et al., GCN #27936) and the source detected earlier by Pozanenko et al. (GCN #27937) as well as the potential host galaxy also mentioned by the latter GCN (coordinates in GCN #27935 suffer the same error). I'm sorry for any inconvenience I may have caused.

We observed the error circle of the short GRB 200623A (Fermi GBM detection and analysis: Fermi GBM Team, GCN #28011, Veres & Meegan, GCN #28019; Swift BAT/GUANO localization: DeLaunay et al., GCN #28013) with the T80 0.8m telescope at the Observatorio de Javalambre (Teruel, Spain). Observations consisted of 3 x 500 s in g', 3 x 500 s in r', 8 x 180 s in i', and 8 x 180 s in z', at midtimes 0.816779, 0.798439, 0.779694, and 0.755722 days after the GRB, respectively. At the position of XRT source #1, the known quasar from the Veron-Cetty & Veron 2006 catalog is clearly detected. At the position of XRT source #2, we clearly detect the source proposed by Belkin et al. (GCN #28020) as a candidate afterglow. Measured against three nearby SDSS comparison stars, we find (AB mags): g' = 23.70 +/- 0.30 mag; r' = 22.55 +/- 0.15 mag; i' = 21.54 +/- 0.15 mag; z' = 20.74 +/- 0.10 mag, indicating this is a very red source. We assume that the observations of Belkin et al. were performed without a filter, this would explain the brighter magnitude they find (their use of comparison stars from the USNO catalog may also play a role). These very red colors are untypical for a GRB afterglow. Furthermore, comparison with images form PanSTARRS clearly reveals a pre-detection of the source at a similar magnitude and color, see: https://www.iaa.csic.es/~deugarte/GRBs/200623A/200623A_color2.jpg for a comparison. We therefore believe it is unlikely that this source is associated with GRB 200623A (additionally, the XRT detection is of low significance for now). At the position of XRT source #3, we detected multiple sources in the vicinity also seen in PanSTARRS imaging. The faint source detected by the TNG (D'Avanzo et al., GCN #28021), may be vaguely detected in our r' and z' images, but it is unclear how much this could be due to the PSF of a nearby bright star. We present a second comparison image here: https://www.iaa.csic.es/~deugarte/GRBs/200623A/200623A_color.jpg No other obviously bright afterglow candidate is detected in the BAT error circle, however, a second epoch of comparable depth would be needed for a more detailed analysis.

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et al. GCN #27797, Fermi GBM detection: Pookalil et al., GCN #27809) with the T80 0.8m telescope at the Observatorio de Javalambre (Teruel, Spain). Observations consisted of 3 x 300 s in g', 2 x 300 s in r', and 5 x 180 s in i' and z' each. The afterglow (Ho et al., GCN #27799, Kumar et al., GCN #27800, Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803, Perley et al., GCN #27805, Kumar et al., GCN #27806, de Ugarte Postigo et al., GCN #27807) is well-detected in each image. In the stacked r' image centered at 21:59:24 UT (mid-time 0.705135 days after the Fermi GBM trigger), we measure r' = 21.08 +/- 0.04 mag (AB mags) against PanSTARRS stars in the field.

In this paper, we analyse how to extract the physical properties from the GALANTE photometry of a stellar sample. We propose a direct comparison between the observational colours (photometric bands normalized to the 515 nm central wavelength) and the synthetic colours derived from different stellar libraries. We use the reduced χ2 as the figure of merit for selecting the best fitting between both colour sets. The synthetic colours of the Next Generation Spectral Library (NGSL) provide a valuable sample for testing the uncertainty and precision of the stellar parameters derived from observational data. Reddening, as an extrinsic stellar physical parameter becomes a crucial variable for accounting for the errors and bias in the derived estimates: the higher the reddenings, the larger the errors and uncertainties in the derived parameters. NGSL colours also enable us to compare different theoretical stellar libraries for the same set of physical parameters, where we see how different catalogues of models can provide very different solutions in a, sometimes, non-linear way. This peculiar behaviour makes us to be cautious with the derived physical parameters obtained from GALANTE photometry without previous detailed knowledge of the theoretical libraries used to this end. In addition, we carry out the experiment of deriving physical stellar parameters from some theoretical libraries, using some other libraries as observational data. In particular, we use the Kurucz and Coelho libraries, as input observational data, to derive stellar parameters from Coelho + TLUSTY and Kurucz + TLUSTY stellar libraries, respectively, for different photometric errors and colour excesses.

The next generation of galaxy surveys will allow us to test one of the most fundamental assumptions of the standard cosmology, i.e. that gravity is governed by the general theory of relativity (GR). In this paper, we investigate the ability of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) to constrain GR and its extensions. Based on the J-PAS information on clustering and gravitational lensing, we perform a Fisher matrix forecast on the effective Newton constant, μ, and the gravitational slip parameter, η, whose deviations from unity would indicate a breakdown of GR. Similar analysis is also performed for the DESI and Euclid surveys and compared to J-PAS with two configurations providing different areas, namely an initial expectation with 4000 deg2 and the future best case scenario with 8500 deg2. We show that J-PAS will be able to measure the parameters μ and η at a sensitivity of 2-7 per cent, and will provide the best constraints in the interval z = 0.3-0.6, thanks to the large number of ELGs detectable in that redshift range. We also discuss the constraining power of J-PAS for dark energy models with a time-dependent equation-of-state parameter of the type w(a) = w0 + wa(1 - a), obtaining ∆w0 = 0.058 and ∆wa = 0.24 for the absolute errors of the dark energy parameters.

We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient events to enhance their follow-up and reduce the delay between the initial detection and optical confirmation. The GRANDMA programme mainly focuses on follow-up of gravitational-wave alerts to find and characterize the electromagnetic counterpart during the third observational campaign of the Advanced LIGO and Advanced Virgo detectors. But it allows for follow-up of any transient alerts involving neutrinos or gamma-ray bursts, even those with poor spatial localization. We present the different facilities, tools, and methods we developed for this network and show its efficiency using observations of LIGO/Virgo S190425z, a binary neutron star merger candidate. We furthermore report on all GRANDMA follow-up observations performed during the first six months of the LIGO-Virgo observational campaign, and we derive constraints on the kilonova properties assuming that the events' locations were imaged by our telescopes.

We observed the position of the Fermi GBM/LAT GRB 200219C (Fermi GBM team, GCN #27145, Hamburg et al., GCN #27155, Dirirsa et al., GCN #27151) with the Javalambre Observatory OAJ 80cm telescope in g'r'i'z', obtaining 3 x 300 s exposures in g'r' each, and 5 x 180 s exposures in i'z' each. Observations started on 2020-02-21, 03:17:55 UT. No observations were obtained the night before as the LAT position came only after twilight had started. In the stacked r' image (midtime 1.14375 days after the GRB), we clearly detect a source within the enhanced XRT error circle (Burrows et al., GCN #27157) for which we measure r'(AB) = 22.11 ± 0.13 mag against PanSTARRS field stars. We note this implies a decay compared with the afterglow discovery by Reva et al. (GCN #27162) who find R ~ 21.72 ± 0.15 mag (AB) about six hours earlier. It is still brighter than the PanSTARRS host galaxy magnitude given by Xu et al. (GCN #27161) at r' = 22.70 ± 0.15 mag. The relatively bright host galaxy may be indicative of a low-redshift event. As the source is improving in visibility and will be observable for several months to come, a search for associated supernova emission may be worthwhile. Spectroscopy is encouraged.

We performed tiled observations of LIGO/Virgo S200213t event with the FRAM-Auger, FRAM-CTA-N, OAJ-T80, TAROT-Calern (TCA), TAROT-Chili (TCH), TAROT-Reunion (TRE) telescopes. FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is located at Observatorio del Roque de los Muchachos. OAJ is located at Javalambre observatory. TCA is located at Calern site at the Cote d'Azur observatory. TCH is located at La Silla ESO observatory (LaS/ESO). TRE is located at Les Makes astronomical observatory.

Context. From the approximately 3500 planetary nebulae (PNe) discovered in our Galaxy, only 14 are known to be members of the Galactic halo. Nevertheless, a systematic search for halo PNe has never been performed. Aims: In this study, we present new photometric diagnostic tools to identify compact PNe in the Galactic halo by making use of the novel 12-filter system projects, Javalambre Photometric Local Universe Survey (J-PLUS) and Southern-Photometric Local Universe Survey (S-PLUS). Methods: We reconstructed the Isaac Newton Telescope Photometric Hα Survey of the Northern Galactic Plane diagnostic diagram and propose four new ones using (i) the J-PLUS and S-PLUS synthetic photometry for a grid of photo-ionisation models of halo PNe, (ii) several observed halo PNe, as well as (iii) a number of other emission-line objects that resemble PNe. All colour-colour diagnostic diagrams are validated using two known halo PNe observed by J-PLUS during the scientific verification phase and the first data release (DR1) of S-PLUS and the DR1 of J-PLUS. Results: By applying our criteria to the DR1s (~1190 deg2), we identified one PN candidate. However, optical follow-up spectroscopy proved it to be a H II region belonging to the UGC 5272 galaxy. Here, we also discuss the PN and two H II galaxies recovered by these selection criteria. Finally, the cross-matching with the most updated PNe catalogue (HASH) helped us to highlight the potential of these surveys, since we recover all the known PNe in the observed area. Conclusions: The tools here proposed to identify PNe and separate them from their emission-line contaminants proved to be very efficient thanks to the combination of many colours, even when applied - like in the present work - to an automatic photometric search that is limited to compact PNe.

The Observatorio Astrofísico de Javalambre (OAJ, Teruel, Spain) has two main telescopes: JST/T250, a 2.5m 3 deg FoV and JAST/T80 with 2 deg FoV. From OAJ two large area multiband photometric sky surveys of 8500 square degrees are being carried out. J-PAS using 54 narrow and 5 broad band filters and J-PLUS using 12 filters. The OAJ also offers 20% of observing time to the community. This contribution presents different web applications designed and implemented at the Centro de Estudios de Física del Cosmos de Aragón (CEFCA) used for a variety of purposes: scheduling and tracking of the different observations, management and data quality review of the products of the reduction pipeline, external access to the data products of the Open Observing Time, and external access and visualization of the images and catalogues of the J-PLUS and J-PAS surveys using services such as images search, cone search, object list search, object visualization, sky navigation and asynchronous queries (ADQL). All web applications have been developed with Python language and PostgreSQL database.

The Centro de Estudios de Física del Cosmos de Aragón (CEFCA) is carrying out two large area multiband photometric sky surveys, J-PLUS and J-PAS, from the Observatorio Astrofísico de Javalambre (OAJ, Teruel, Spain) covering the entire optical spectrum using narrow and broad band filters. As an effort to make the data public, we offer Virtual Observatory (VO) compliant services to make the access to the data more versatile through the multiple VO compliant existent tools. For example, catalogues are offered through TAP protocol and images can be searched and downloaded using the SIAP protocol. This contribution summarizes why we decided to make our own implementation, the process we followed to choose which services to implement according to the kind of data generated by the survey, why Python and PostgreSQL were chosen and, finally, the lessons learned.

Aims: We present the photometric calibration of the 12 optical passbands observed by the Javalambre Photometric Local Universe Survey (J-PLUS). Methods: The proposed calibration method has four steps: (i) definition of a high-quality set of calibration stars using Gaia information and available 3D dust maps; (ii) anchoring of the J-PLUS gri passbands to the Pan-STARRS photometric solution, accounting for the variation in the calibration with the position of the sources on the CCD; (iii) homogenization of the photometry in the other nine J-PLUS filters using the dust de-reddened instrumental stellar locus in (

We present a synthetic galaxy lightcone specially designed for narrow-band optical photometric surveys. To reduce time-discreteness effects, unlike previous works, we directly include the lightcone construction in the L-Galaxies semi-analytic model applied to the subhalo merger trees of the Millennium simulation. Additionally, we add a model for the nebular emission in star-forming regions, which is crucial for correctly predicting the narrow- and medium-band photometry of galaxies. Specifically, we consider, individually for each galaxy, the contribution of 9 different lines: Lyα (1216 Å), Hβ (4861 Å), Hα (6563 Å), [O II] (3727 Å, 3729 Å), [O III] (4959 Å, 5007 Å), [Ne III] (3870 Å), [O I] (6300 Å), [N II] (6548 Å, 6583 Å), and [S II] (6717 Å, 6731 Å). We validate our lightcone by comparing galaxy number counts, angular clustering, and Hα, Hβ, [O II], and [O III]5007 luminosity functions to a compilation of observations. As an application of our mock lightcones, we generated catalogues tailored for J-PLUS, a large optical galaxy survey featuring five broad-band and seven medium-band filters. We study the ability of the survey to correctly identify, with a simple three-filter method, a population of emission-line galaxies at various redshifts. We show that the 4000 Å break in the spectral energy distribution of galaxies can be misidentified as line emission. However, all significant excess (> 0.4 mag) can be correctly and unambiguously attributed to emission-line galaxies. Our catalogues are publicly released to facilitate their use in interpreting narrow-band surveys and in quantifying the impact of line emission in broad-band photometry.

Context. Between the blue cloud and the red sequence peaks on the galaxy colour-magnitude diagram there is a region sparsely populated by galaxies called the green valley. In a framework where galaxies mostly migrate on the colour-magnitude diagram from star forming to quiescent, the green valley is considered a transitional galaxy stage. The details of the processes that drive galaxies from star-forming to passive systems still remain unknown. Aims: We aim to measure the transitional timescales of nearby galaxies across the green valley, through the analysis of Galaxy Evolution Explorer and Javalambre Photometric of Local Universe Survey photometric data. Specifically, we seek to study the impact of bars on the quenching timescales. Methods: We developed a method that estimates empirically the star formation quenching timescales of green valley galaxies, assuming an exponential decay model of the star formation histories and through a combination of narrow and broad bands from the Javalambre Photometric of Local Universe Survey and Galaxy Evolution Explorer. We correlated these quenching timescales with the presence of bars. Results: We find that the Javalambre Photometric of Local Universe Survey colours F0395 -g and F0410 -g are sensitive to different star formation histories, showing, consequently, a clear correlation with the Dn(4000) and Hδ, A spectral indices. We measured quenching timescales based on these colours and we find that quenching timescales obtained with our new approach are in agreement with those determined using spectral indices. We also compared the quenching timescales of green valley disc galaxies as a function of the probability of hosting a bar. We find that galaxies with high bar probability tend to quench their star formation slowly. Conclusions: We conclude that: (1) Javalambre Photometric of Local Universe Survey filters can be used to measure quenching timescales in nearby green valley galaxies; and (2) the resulting star formation quenching timescales are longer for barred green valley galaxies. Considering that the presence of a bar indicates that more violent processes (e.g. major mergers) are absent in host galaxies, we conclude that the presence of a bar can be used as a morphological signature for slow star formation quenching.

We estimate the constraining power of Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) for parameters of an interacting dark energy (DE) cosmology. The survey is expected to map several millions of luminous red galaxies, emission line galaxies, and quasars in an area of thousands of square degrees in the northern sky with precise photometric redshift measurements. Forecasts for the DESI and Euclid surveys are also evaluated and compared to J-PAS. Using the Fisher matrix approach, we find that J-PAS can place constraints on the interaction parameter comparable to those from DESI, with an absolute uncertainty of about 0.02, when the interaction term is proportional to the dark matter energy density, and almost as good, of about 0.01, when the interaction is proportional to the DE density. For the equation of state of DE, the constraints from J-PAS are slightly better in the two cases (uncertainties 0.04-0.05 against 0.05-0.07 around the fiducial value -1). Both surveys stay behind Euclid but follow it closely, imposing comparable constraints in all specific cases considered.

Context. Ultracool dwarfs are objects with spectral types equal to or later than M7. Most of them have been discovered using wide-field imaging surveys. The Virtual Observatory has proven to be very useful for efficiently exploiting these astronomical resources. Aims: We aim to validate a Virtual Observatory methodology designed to discover and characterise ultracool dwarfs in the J-PLUS photometric survey. J-PLUS is a multiband survey carried out with the wide-angle T80Cam optical camera mounted on the 0.83 m telescope JAST/T80 in the Observatorio Astrofísico de Javalambre. We make use of the Internal Data Release covering 528 deg2. Methods: We complemented J-PLUS photometry with other catalogues in the optical and infrared using VOSA, a Virtual Observatory tool that estimates physical parameters from the spectral energy distribution fitting to collections of theoretical models. Objects identified as ultracool dwarfs were distinguished from background M giants and highly reddened stars using parallaxes and proper motions from Gaia DR2. Results: We identify 559 ultracool dwarfs, ranging from i = 16.2 mag to i = 22.4 mag, of which 187 are candidate ultracool dwarfs not previously reported in the literature. This represents an increase in the number of known ultracool dwarfs of about 50% in the region of the sky we studied, particularly at the faint end of our sensitivity, which is interesting as reference for future wide and deep surveys such as Euclid. Three candidates are interesting targets for exoplanet surveys because of their proximity (distances less than 40 pc). We also analysed the kinematics of ultracool dwarfs in our catalogue and found evidence that it is consistent with a Galactic thin-disc population, except for six objects that might be members of the thick disc. Conclusion. The results we obtained validate the proposed methodology, which will be used in future J-PLUS and J-PAS releases. Considering the region of the sky covered by the Internal Data Release used in this work, we estimate that 3000-3500 new ultracool dwarfs will be discovered at the end of the J-PLUS project.

Observatories and satellites around the globe produce tremendous amounts of imaging data to study many different astrophysical phenomena. The serendipitous observations of Solar System objects are a fortunate by-product which have often been neglected due to the lack of a simple yet efficient identification algorithm. Meanwhile, the determination of the orbit, chemical composition, and physical properties such as rotation period and 3D-shape of Solar System objects requires a large number of astrometry and multi-band photometry observations. Such observations are hidden in current and future astrophysical archives, and a method to harvest these goldmines is needed. This article presents an easy-to-implement, light-weight software package which detects bodies of the Solar System in astronomical images and measures their astrometry and photometry. The ssos pipeline is versatile, allowing for application to all kinds of observatory imaging products. The sole principle requirement is that the images observe overlapping areas of the sky within a reasonable time range. Both known and unknown Solar System objects are recovered, from fast-moving near-Earth asteroids to slow objects in the distant Kuiper belt. The high-level pipeline design and two test applications are described here, highlighting the versatility of the algorithm with both narrow-field pointed and wide-field survey observations. In the first study, 2,828 detections of 204 SSOs are recovered from publicly available images of the GTC OSIRIS Broad Band DR1 (Cortés-Contreras, in preparation). The false-positive ratio of SSO detections ranges from 0% - 23% depending on the pipeline setup. The second test study utilizes the images of the first data release of J-PLUS, a 12-band optical survey. 4,606 SSO candidates are recovered, with a false-positive ratio of (2.0 ± 0.2)%. A stricter pipeline parameter setup recovers 3,696 candidates with a sample contamination below 0.68%.

This paper describes the characterization of the GALANTE photometric system, a seven intermediate- and narrow-band filter system with a wavelength coverage from 3000 Å to 9000 Å. We describe the photometric system presenting the full sensitivity curve as a product of the filter sensitivity, CCD, telescope mirror, and atmospheric transmission curves, as well as some first- and second-order moments of this sensitivity function. The GALANTE photometric system is composed of four filters from the J-PLUS photometric system, a twelve broad-to-narrow filter system, and three exclusive filters, specifically designed to measure the physical parameters of stars such as effective temperature Teff, log (g), metallicity, colour excess E(4405 - 5495), and extinction type R5495. Two libraries, the Next Generation Spectral Library (NGSL) and the one presented in Maíz Apellániz & Weiler (2018), have been used to determine the transformation equations between the Sloan Digital Sky Survey (SDSS) ugriz photometry and the GALANTE photometric system. We will use this transformation to calibrate the zero-points of GALANTE images. To this end, a preliminary photometric calibration of GALANTE has been made based on two different griz libraries (SDSS DR12 and ATLAS All-Sky Stellar Reference Catalog, hereinafter RefCat2). A comparison between both zero-points is performed leading us to the choice of RefCat2 as the base catalogue for this calibration, and applied to a field in the Cyg OB2 association.

We checked the magnitude of our second-epoch OSN observation (Kann et al., GCN 24700) of the Fermi GBM/LAT GRB 190530A (Fermi GBM team, GCN 24676; Longo et al., GCN 24679) and found a calculation error which resulted in an incorrect zero-point. Remeasuring the magnitude against four SDSS stars (once again transformed to Rc via the equations of Lupton 2005) we now derive Rc(AB) = 19.51 +/- 0.04 mag. This is in good agreement with the value obtained by Moskvitin & Uklein (GCN 24708). The magnitude of Belkin et al. (GCN 24698) is still overly bright compared to our new result, and the revised value from Vinko et al. (GCN 24751) is now significantly fainter. We obtained 7 x 300 s images in SDSS r' with the 0.8m telescope of the Observatorio Astrofisico de Javalambre (Teruel, Spain). The first three images were taken too early in twilight and were discarded. The afterglow is clearly detected in the stack of the four last images, and we measure: r'(AB) = 20.27 +/- 0.06 mag at 2.43735 days after the GRB. This is in good agreement with an earlier value from Vinko et al. (GCN 24751) combined with a steep decay. Using the further photometry published since Kann et al. (GCN 24700) (Moskvitin et al., GCN 24708; Belkin et al., GCN 24712; Kumar et al., GCN 24729; Nandi et al., GCN 24745; Vinko et al., GCN 24751) we find: - The steep decay between the observation of Watson et al. (GCN 24690) and Xin et al. (GCN 24697) remains, and is not significantly affected by our revised OSN measurement. - There may be a small flare at 1.4 days (this GCN [OSN]; Moskvitin et al., GCN 24708). - Starting at 2.2 days (Belkin et al., GCN 24712; Vinko et al., GCN 24751; this GCN [OAJ]; Nandi et al., GCN 24745; Kumar et al., GCN 24729), yet another steep decay sets in, for which we measure alpha = 3.72 +/- 0.43. This value is perfectly in agreement with the one derived in Kann et al. (GCN 24700) at an earlier time, but now based on significantly more measurements. Further follow-up is warranted, if possible.

GALANTE is an optical photometric survey with seven intermediate/narrow filters that has been covering the Galactic Plane since 2016 using the Javalambre T80 and Cerro Tololo T80S telescopes. The P.I.s of the northern part (GALANTE NORTE) are Emilio J. Alfaro and Jes\'us Ma\'iz Apell\'aniz. and the P.I. of the southern part (GALANTE SUR) is Rodolfo H. Barb\'a. The detector has a continuous 1.4 degr x 1.4 degr field of view with a sampling of 0.55"/pixel and the seven filters are optimized to detect obscured early-type stars. The survey includes long, intermediate, short, and ultrashort exposure times to reach a dynamical range close to 20 magnitudes, something never achieved for such an optical project before. The characteristics of GALANTE allow for a new type of calibration scheme using external Gaia, Tycho-2, and 2MASS data that has already led to a reanalysis of the sensitivity of the Gaia G filter. We describe the project and present some early results. GALANTE will identify the majority of the early-type massive stars within several kpc of the Sun and measure their amount and type of extinction. It will also map the Halpha nebular emission, identify emission-line stars, and do other studies of low- and intermediate-mass stars.

The Javalambre Photometric Local Universe Survey (J-PLUS; Cenarro et al. 2018), is observing thousands of square degrees of the northern sky from the Observatorio Astrofísico de Javalambre (OAJ) in Teruel, Spain. The survey is being carried out with the 0.83 meter JAST/T80 telescope and the panoramic camera T80Cam with a 2 deg² FoV. A set of twelve broad, intermediate, and narrow band optical filters is used. The large FoV, the position of the filters, and the survey strategy; are suitable to perform science that will expand our knowledge in many fields of astrophysics. More concretely, the J0660 narrow-band filter covers the Hα emission-line flux of nearby galaxies up to z ≤ 0.017, making J-PLUS a powerful tool to study the 2D star formation rate (SFR) properties of these galaxies.

The First Data release of the J-PLUS photometric survey is already public and available for the scientific community. It includes millions of sources in a usable area of 897 deg². With it, we analyse nearby star-forming galaxies (z<0.017) to obtain the Hα Luminosity Function of the Local Universe, the Star Formation Main Sequence, and the Star Formation Rate Density of the Local Universe. Our results are the most local values for these properties, using a large and homogeneous sample of sources with no target pre-selection.

We present the first data release of the Javalambre Local Universe Photometric Survey (J-PLUS), an ongoing photometric survey with 12 optical bands observing thousands of square degrees of the sky from the JAST/T80 telescope at the Observatorio Astrofísico de Javalambre (OAJ). T80Cam is a 2 deg² field-of-view (FoV) camera mounted on JAST/T80, and is equipped with a unique system of filters spanning the entire optical range (3500 - 10000 Å), optimally designed to extract the rest-frame spectral features that are key to both characterize stellar types and to deliver a low-resolution photo-spectrum for each observed object. With a typical depth (5σ in 3 arcsec aperture) of AB~20.7 mag per band, we release the first 1022 deg² of J-PLUS data, containing about 4.3 million stars and 3.0 million galaxies at r < 21 mag.

The large and indiscriminate area Javalambre Photometric Local Universe Survey (J-PLUS) will observe, together with the survey's depth, mag_{AB}=22 in the broad bands, makes it very convenient for deriving properties of the Galactic halo structure. Among the stars than can be used for that purpose, RR Lyrae pulsating stars are of outstanding importance for several reasons (see e.g. Sarajedini 2011): i) they are ubiquitous species in our Galaxy, so they can be found distributed virtually everywhere without being linked to any particular Galactic component; ii) they are relatively bright (M_{V}˜0.6 for mean halo metallicity), so they are easily detectable up to a few hundred kpc from us; iii) their pulsation periods obey a period-luminosity-metallicity relation that makes them standard candles, becoming very useful to constraint distances; iv) they are stars older than 10 Gyr, so they are fair tracers of the Milky Way old component. J-PLUS will provide the SED of a unprecedented amount of RR Lyrae stars. Here, the first preliminary mandatory step towards the achievement of those goals is addressed: the development of a method allowing the identification of RR Lyrae star candidates. The stellar locus of the RR Lyraes at different color-color spaces is inspected in order to isolate highly pure and complete candidate samples. A machine-learning technique is applyied, employing Gaia DR2 identifications (which are complete for Gaia's G≲ 17) for building the training and test sets. The resulting completeness is 85% with a purity of 77%, obtaining ˜ 5,000 RR Lyrae stars candidates with 17.0≤ r ≤ 19 in J-PLUS DR1. That result is using J-PLUS colors only. A significant improvement is expected when including variability information, e.g. from the comparison of J-PLUS photometry with other archives. This methodology will be applied to the whole survey data.

The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is an unprecedented photometric sky survey of 8,500 deg^2 visible from the Observatorio Astrofísico de Javalambre (OAJ) in 59 colors, using a set of broad, intermediate and narrow band filters. J-PAS is going to provide the first complete 3D map of a large volume of the Universe and will contribute on many astrophysical science cases, from Solar System minor bodies to Cosmology. The survey will be conducted by the Javalambre Survey Telescope, JST/T250, with Javalambre Panoramic Camera (JPCam), which is currently in its engineering phase. Until then, the interim JPAS-Pathfinder camera, mounting a single CCD covering the center of the FoV, is installed at the telescope. Its filter wheel is ready to host the J-PAS filters already available for use on sky. This is permitting the commissioning of the equipment and is providing the first scientific data: the mini J-PAS. The up-to-date JPAS-Pathfinder commissioning and the results of the science operation is summarized here.

The first JPLUS Data Release (July 2018) provided data in 12 filters, covering a total area of 1022 deg^2, collected from November 2015 to January 2018 by the JAST/T80 telescope. The JPLUS Consortium aims to include the astrophysical parameters of the sources in the JPLUS DR1 added value catalogue. As a first step temperatures are derived for a small set of stars (Gold sample) with the best photometric precision in all filters. This work derives temperatures from JPLUS colours of this Gold sample. The addition of Gaia mission second release (GDR2, April 2018) information, with magnitudes, parallaxes and colours for more than one billion sources is very useful to determine the astrophysical parameters of the stellar content in JPLUS data. In particular, the use of Gaia parallaxes are used to improve the characterisation of the observed sources.

The intracluster light (ICL) is a luminous component of galaxy clusters composed of stars that are gravitationally bound to the cluster potential but do not belong to the individual galaxies. Previous studies of the ICL have shown that its formation and evolution are intimately linked to the evolutionary stage of the cluster. Thus, the analysis of the ICL in the Coma cluster will give insights into the main processes driving the dynamics in this highly complex system. Using a recently developed technique, we measure the ICL fraction in Coma at several wavelengths, using the J-PLUS unique filter system. The combination of narrow- and broadband filters provides valuable information on the dynamical state of the cluster, the ICL stellar types, and the morphology of the diffuse light. We use the Chebyshev-Fourier Intracluster Light Estimator (CICLE) to disentangle the ICL from the light of the galaxies, and to robustly measure the ICL fraction in seven J-PLUS filters. We obtain the ICL fraction distribution of the Coma cluster at different optical wavelengths, which varies from ~ 7%-21%, showing the highest values in the narrowband filters J0395, J0410, and J0430. This ICL fraction excess is distinctive pattern recently observed in dynamically active clusters (mergers), indicating a higher amount of bluer stars in the ICL compared to the cluster galaxies. Both the high ICL fractions and the excess in the bluer filters are indicative of a merging state. The presence of younger/lower-metallicity stars the ICL suggests that the main mechanism of ICL formation for the Coma cluster is the stripping of the stars in the outskirts of infalling galaxies and, possibly, the disruption of dwarf galaxies during past/ongoing mergers.

In the present paper we aim to validate a methodology designed to extract the Halpha emission line flux from J-PLUS photometric data. J-PLUS is a multi narrow-band filter survey carried out with the 2 deg^2 field of view T80Cam camera, mounted on the JAST/T80 telescope in the OAJ, Teruel, Spain. The information of the twelve J-PLUS bands, including the J0660 narrow-band filter located at rest-frame Halpha, is used over 42 deg2 to extract de-reddened and [NII] decontaminated Halpha emission line fluxes of 46 star-forming regions with previous SDSS and/or CALIFA spectroscopic information. The agreement of the inferred J-PLUS photometric Halpha fluxes and those obtained with spectroscopic data is remarkable, with a median comparison ratio R = 1.05 +- 0.25. This demonstrates that it is possible to retrieve reliable Halpha emission line fluxes from J-PLUS photometric data. With an expected area of thousands of square degrees upon completion, the J-PLUS dataset will allow the study of several star formation science cases in the nearby universe, as the spatially resolved star formation rate of nearby galaxies at z < 0.015, and how it is influenced by the environment, morphology or nuclear activity. As an illustrative example, the close pair of interacting galaxies NGC3994 and NGC3995 is analyzed, finding an enhancement of the star formation rate not only in the center, but also in outer parts of the disk of NGC3994.

The Javalambre Photometric Local Universe Survey (J-PLUS) provides wide field-of-view images in 12 narrow, intermediate and broad-band filters optimized for stellar photometry. Here we have applied J-PLUS data for the first time for the study of Galactic GCs using science verification data obtained for the very metal-poor GC M\,15. Our J-PLUS data provide low-resolution spectral energy distributions covering the near-UV to the near-IR, allowing us to search for MPs based on pseudo-spectral fitting diagnostics. J-PLUS CMDs are found to be particularly useful to search for splits in the sequences formed by the upper red giant branch (RGB) and asymptotic giant branch (AGB) stars. We interpret these split sequences as evidence for the presence of MPs. This demonstrates that the J-PLUS survey will have sufficient spatial coverage and spectral resolution to perform a large statistical study of GCs through multi-band photometry in the coming years.

The spatial variations of stellar population properties within a galaxy are intimately related to their formation process. Therefore, spatially resolved studies of galaxies are essential to uncover their formation and assembly. The Javalambre Photometric Local Universe Survey (J-PLUS) is a dedicated multi-filter designed to observed ~8500 deg^2 using twelve narrow-, intermediate- and broad-band filters in the optical range. In this study, we test the potential of the multi-filter observation carried out with J-PLUS to investigate the properties of spatially-resolved nearby galaxies. We present detailed 2D maps of stellar population properties (age, metallicity, extinction, and stellar mass surface density) for two early-type galaxies observed in both, J-PLUS and CALIFA surveys: NGC 5473 and NGC 5485. Radial structures are also compared and luminosity- and mass-weighted profiles are derived. We use MUFFIT to process the J-PLUS observations, and two different techniques (STARLIGHT and STECKMAP) to analyze IFU CALIFA data. We demonstrate that this novel technique delivers radial stellar population gradients in good agreement with the IFU technique CALIFA/STECKMAP although comparison of the absolute values reveals the existence of intrinsic systematic differences. Radial stellar population gradients differ when CALIFA/STARLIGHT methodology is used. Age and metallicity radial profiles derived from J-PLUS/MUFFIT are very similar when luminosity- or mass-weighted properties are used, suggesting that the contribution of a younger component is small. Comparison between the three methodologies reveals some discrepancies suggesting that the specific characteristics of each method causes important differences. We conclude that the ages, metallicities and extinction derived for individual galaxies not only depend on the chosen models but also depend on the method used.

We aim to use multi-band imaging from the Phase-3 Verification Data of the J-PLUS survey to derive accurate photometric redshifts (photo-z) and look for potential new members in the surroundings of the nearby galaxy clusters A2589 (z=0.0414) & A2593 (z=0.0440), using redshift probability distribution functions. The ultimate goal is to demonstrate the usefulness of a 12-band filter system in the study of large-scale structure in the local universe. We present an optimized pipeline for the estimation of photo-z in clusters of galaxies. We tested our photo-z with a sample of 296 spectroscopically confirmed cluster members with a magnitude of = 16.6 and redshift =0.041. The combination of seven narrow and five broadband filters with a typical photometric-depth of r<21.5 provides dz/(1+z)=0.01 photo-z estimates. A precision of dz/(1+z)=0.005 is obtained for the 177 galaxies brighter than magnitude r<17. To foresee the precision beyond the spectroscopic sample, we designed a set of simulations in which real cluster galaxies are modeled and reinjected inside the images at different signal-to-noise. A precision of dz/(1+z)=0.02 and dz/(1+z)=0.03 is expected at = 18-22, respectively. Complementarily, we used SDSS/DR12 data to derive photo-z estimates for the same galaxy sample, demonstrating that the wavelength-resolution of the J-PLUS can double the precision achieved by SDSS for galaxies with a high S/N. We find as much as 170 new candidates across the entire field. The spatial distribution of these galaxies may suggest an overlap between the systems with no evidence of a clear filamentary structure connecting the clusters. These preliminary results show the potential of J-PLUS data to revisit membership of groups and clusters from nearby galaxies, important for the determination of luminosity and mass functions and environmental studies at the intermediate and low-mass regime.

Our goal is to morphologically classify the sources identified in the images of the J-PLUS early data release (EDR) into compact (stars) or extended (galaxies) using a suited Bayesian classifier. J-PLUS sources exhibit two distinct populations in the r-band magnitude vs. concentration plane, corresponding to compact and extended sources. We modelled the two-population distribution with a skewed Gaussian for compact objects and a log-normal function for the extended ones. The derived model and the number density prior based on J-PLUS EDR data were used to estimate the Bayesian probability of a source to be star or galaxy. This procedure was applied pointing-by-pointing to account for varying observing conditions and sky position. Finally, we combined the morphological information from g, r, and i broad bands in order to improve the classification of low signal-to-noise sources. The derived probabilities are used to compute the pointing-by-pointing number counts of stars and galaxies. The former increases as we approach to the Milky Way disk, and the latter are similar across the probed area. The comparison with SDSS in the common regions is satisfactory up to r ~ 21, with consistent numbers of stars and galaxies, and consistent distributions in concentration and (g - i) colour spaces. We implement a morphological star/galaxy classifier based on PDF analysis, providing meaningful probabilities for J-PLUS sources to one magnitude deeper (r ~ 21) than a classical boolean classification. These probabilities are suited for the statistical study of 150k stars and 101k galaxies with 15 < r < 21 present in the 31.7 deg2 of the J-PLUS EDR. In a future version of the classifier, we will include J-PLUS colour information from twelve photometric bands.

J-PLUS is an ongoing 12-band photometric optical survey, observing thousands of square degrees of the Northern hemisphere from the dedicated JAST/T80 telescope at the Observatorio Astrofísico de Javalambre. T80Cam is a 2 sq.deg field-of-view camera mounted on this 83cm-diameter telescope, and is equipped with a unique system of filters spanning the entire optical range. This filter system is a combination of broad, medium and narrow-band filters, optimally designed to extract the rest-frame spectral features (the 3700-4000 Å Balmer break region, H_delta, Ca H+K, the G-band, the Mgb and Ca triplets) that are key to both characterize stellar types and to deliver a low-resolution photo-spectrum for each pixel of the sky observed. With a typical depth of AB ~ 21.25 mag per band, this filter set thus allows for an indiscriminate and accurate characterization of the stellar population in our Galaxy, it provides an unprecedented 2D photo-spectral information for all resolved galaxies in the local universe, as well as accurate photo-z estimates (Delta_z~ 0.01-0.03) for moderately bright (up to r ~ 20 mag) extragalactic sources. While some narrow band filters are designed for the study of particular emission features ([OII]/lambda3727, H_alpha/lambda6563) up to z < 0.015, they also provide well-defined windows for the analysis of other emission lines at higher redshifts. As a result, J-PLUS has the potential to contribute to a wide range of fields in Astrophysics, both in the nearby universe (Milky Way, 2D IFU-like studies, stellar populations of nearby and moderate redshift galaxies, clusters of galaxies) and at high redshifts (ELGs at z~0.77, 2.2 and 4.4, QSOs, etc). With this paper, we release ~36 deg² of J-PLUS data, containing about 1.5 x 10^5 stars and 10^5 galaxies at r<21 mag.

Context. We present a new methodology for the estimation of stellar atmospheric parameters from narrow- and intermediate-band photometry of the Javalambre Photometric Local Universe Survey (J-PLUS), and propose a method for target pre-selection of low-metallicity stars for follow-up spectroscopic studies. Photometric metallicity estimates for stars in the globular cluster M15 are determined using this method. Aims: By development of a neural-network-based photometry pipeline, we aim to produce estimates of effective temperature, Teff, and metallicity, [Fe/H], for a large subset of stars in the J-PLUS footprint. Methods: The Stellar Photometric Index Network Explorer, SPHINX, was developed to produce estimates of Teff and [Fe/H], after training on a combination of J-PLUS photometric inputs and synthetic magnitudes computed for medium-resolution (R 2000) spectra of the Sloan Digital Sky Survey. This methodology was applied to J-PLUS photometry of the globular cluster M15. Results: Effective temperature estimates made with J-PLUS Early Data Release photometry exhibit low scatter, σ(Teff) = 91 K, over the temperature range 4500 < Teff (K) < 8500. For stars from the J-PLUS First Data Release with 4500 < Teff (K) < 6200, 85 ± 3% of stars known to have [Fe/H] < -2.0 are recovered by SPHINX. A mean metallicity of [Fe/H] = - 2.32 ± 0.01, with a residual spread of 0.3 dex, is determined for M15 using J-PLUS photometry of 664 likely cluster members. Conclusions: We confirm the performance of SPHINX within the ranges specified, and verify its utility as a stand-alone tool for photometric estimation of effective temperature and metallicity, and for pre-selection of metal-poor spectroscopic targets.

We have observed the field of GRB 180914B (Ursi et al., GCN 23226; Verrecchia et al., GCN 23231; Bissaldi et al. GCN 23232; Ursi et al., GCN 23236) with the 0.8m T80 telescope of the Javalambre Astrophysical Observatory (Teruel, Spain). The observation consisted of 12x300s i-band exposures, each covering the complete LAT error box. The exposures started at 22:03:46 UT of the 15th September, 27.68 hr after the burst. The counterpart identified by Zheng & Filippenko (GCN 23237) and Troja et al. (GCN 23238) is well detected in the individual images. Photometry of the first epoch, as compared with SDSS reference stars yields i(AB)=18.84+/-0.03. Comparing with the RATIR photometry (roja et al. GCN 23238), our photometry implies a decay rate of alpha ~ -1.9 (where F_nu ~ t^alpha), indicating that the afterglow has possibly entered a post-jet-break regime evolution.

The study of Cataclysmic Variables (CVs) is crucial to test our understanding of binary evolution and its application to many astrophysical phenomena, such as short gamma-ray bursts, X-ray transients and, more important, Supernovae Ia, our yardsticks for measuring distances. Yet, the predicted major component of the present-day CV population, the so-called "period bouncers" (CVs containing a white dwarf and a degenerate donor), has not been detected, highlighting a major discrepancy between theory and observations. We present here CHiCaS, the Compact binary HIgh CAdence Survey, which will perform three hours of uninterrupted time series photometry over 136 square degrees of the sky with JAST/T80Cam. By the end of next year, this program will deliver one minute cadence lightcurves for ≃2.5≃2.5 million objects as faint as g≃21.5g≃21.5, along with full colour information. Via detection of their eclipses, CHiCaS will finally, and unambiguously identify the predicted large population of period bouncers. The identification of the missing population will provide an observational support for the current models for the mechanisms of angular momentum loss in compact binaries, which also describe the evolution of all kind of binaries. CHiCaS will also offer a complete and unbiased view into the short term variability of thousands of binaries, eclipsing systems, pulsating stars and CVs in the period gap, which will allow to improve our knowledge of these objects and to carry out additional tests on CV evolution.

Cataclysmic Variables (CVs) are one of the best classes to test our understanding of the evolution of compact, interacting binaries: they are numerous, relatively bright, and both stellar components are structurally simple. Nonetheless, our recent results from a large HST program (Pala et al. 2017) have highlighted a number of discrepancies between current population models and observations. Only once these discrepancies are resolved we can trust the theoretical models to be sensibly applied to more complex systems, such as black hole binaries, X-ray transients or SN Ia progenitors.In particular, one of the most striking disagreements is the lack of period bouncers, i.e. old CVs in which the companions have been eroded down to brown dwarf masses. These systems are predicted to make up for ≃ 70% of the observed CV population, yet very few have been identified so far, suggesting that the physical mechanisms driving CV evolution (such as the mechanisms of angular momentum loss, the common envelope phase and/or the response of the companions to the mass loss) are still not completely understood. For this reason we have started a high cadence photometric survey using JAST/T80Cam aimed to find these elusive systems and we present here the preliminary results from this observing program.

We observed the field of the Swift-BAT GRB 180720B (Siegel et al. GCN 22973), detected also by Fermi-LAT (Bissaldi et al. GCN 22980), with the 0.8m telescope of the Observatorio Astrofisico de Javalambre (Teruel, Spain). Observations consisted of a series of 3x300 s griz exposures, starting at 01:12:55 UT (10.85 hr after the GRB trigger). The afterglow is clearly detected at a position consistent with the one reported by Martone et al. (GCN 22976). We measure a magnitude of r(AB) = 17.77+/- 0.05 mag at an average time of 01:37:14 UT (11.26 hr after the GRB trigger), as compared to nearby SDSS stars.

The Observatorio Astrofísico de Javalambre is a fully automated astronomical observatory particularly conceived for carrying out large sky surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view. The most immediate objective of the two telescopes for the next years is carrying out two unique photometric surveys of several thousands square degrees, Javalambre Phtometry of the Accelerating universe Survey (J-PAS) and Javalambre Photometry of the Local Universe Survey (J-PLUS), each of them with a wide range of scientific applications, like e.g. large structure cosmology and dark energy, galaxy evolution, supernovae, Milky Way structure, among others. To do that, JST and JAST will be equipped with panoramic cameras under development within the J-PAS collaboration, JPCam and T80Cam respectively, which make use of large format ( 10k x 10k) CCDs covering the entire focal plane. This paper describes in detail, from operations point of view, the engineering development of the overall facilities and infrastructures for the robotic observatory and a global overview of current status pinpointing lessons learned in order to boost observatory operations performance achieving scientific targets, maintaining quality requirements but also minimizing resources, material and human resources. We also briefly introduce the Early Data Release (EDR) of J-PLUS, which is already freely accessible worldwide, and the first scientific papers. Finally, we show the next steps necessary for JST to perform the J-PAS project.

The Javalambre Survey Telescope (JST/T250) is a wide-field 2.6 m telescope ideal for carrying out large sky photometric surveys from the Javalambre Astrophysical Observatory in Teruel, Spain. The most immediate goal of JST is to perform J-PAS, a survey of several thousands square degrees of the Northern sky in 59 optical bands, 54 of them narrow (˜ 145 Å FWHM) and contiguous. J-PAS will provide a low resolution photo-spectrum for every pixel of the sky, hence promising crucial breakthroughs in Cosmology and Astrophysics. J-PAS will be conducted with JPCam, a camera with a mosaic of 14 CCDs of 9.2k × 9.2k pix, more than 1200 Mpix and an effective FoV of 4.3 deg2 . Before JPCam is on telescope, the project will work in 2018 with an interim camera, JPAS-Pathfinder, with a reduced FoV of ˜ 0.6 × 0.6 deg2 to perform commissioning and the first JST science. This paper presents the current status and performance of the JST telescope, describing the commissioning and first science of the JPAS-Pathfinder at JST.

Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and a high accretion rate, which is the most promising candidate for the single-degenerate progenitor of a Type Ia supernova known to date. The previous three eruptions of M31N 2008-12a have displayed remarkably homogeneous multiwavelength properties: (i) from a faint peak, the optical light curve declined rapidly by two magnitudes in less than two days, (ii) early spectra showed initial high velocities that slowed down significantly within days and displayed clear He/N lines throughout, and (iii) the supersoft X-ray source (SSS) phase of the nova began extremely early, six days after eruption, and only lasted for about two weeks. In contrast, the peculiar 2016 eruption was clearly different. Here we report (i) the considerable delay in the 2016 eruption date, (ii) the significantly shorter SSS phase, and (iii) the brighter optical peak magnitude (with a hitherto unobserved cusp shape). Early theoretical models suggest that these three different effects can be consistently understood as caused by a lower quiescence mass accretion rate. The corresponding higher ignition mass caused a brighter peak in the free-free emission model. The less massive accretion disk experienced greater disruption, consequently delaying the re-establishment of effective accretion. Without the early refueling, the SSS phase was shortened. Observing the next few eruptions will determine whether the properties of the 2016 outburst make it a genuine outlier in the evolution of M31N 2008-12a.

Summary of the data processing and calibration procedures for the J-PLUS Early Data Release.

We present a morphological classification of J-PLUS EDR sources into compact (i.e. stars) and extended (i.e. galaxies). Such classification is based on the Bayesian modelling of the concentration distribution, including observational errors and magnitude + sky position priors. We provide the star / galaxy probability of each source computed from the gri images. The comparison with the SDSS number counts support our classification up to r 21. The 31.7 deg² analised comprises 150k stars and 101k galaxies.

Located at the Observatorio Astrofísico de Javalambre, the ’’Javalambre Auxiliary Survey Telescope’’ is an 80cm telescope with a unvignetted 2 square degrees field of view. The telescope is equipped with T80Cam, a camera with a large format CCD and two filter wheels which can host, at any given time, 12 filters. The telescope has been designed to provide optical quality all across the field of view, which is achieved with a field corrector. In this talk, I will review the commissioning of the telescope. The optical performance in the centre of the field of view has been tested with lucky imaging technique, providing a telescope PSF of 0.4’’, which is close to the one expected from theory. Moreover, the tracking of the telescope does not affect the image quality, as it has been shown that stars appear round even in exposures of 10minutes obtained without guiding. Most importantly, we present the preliminary results of science verification observations which combine the two main characteristics of this telescope: the large field of view and the special filter set.

In the framework of the Science Verification Phase of T80Cam of the 83cm Javalambre Auxiliary Survey Telescope (JAST80) located at the Observatorio Astrofísico de Javalambre (OAJ), Teruel, Spain, a program was proposed to study the variability of RR Lyrae stars, as well as other variable sources, belonging to the Galactic globular cluster M15. The observations were carried out on different epochs (almost a dozen different nights along a ~4 months period) using the complete set of 12 filters, centered at the optical spectral range, that are being devoted to the exectuion of the ongoing Javalambre Photometric Local Universe Survey (J-PLUS). One of the main goals is the characterization of the variability of the spectral energy distribution of RR Lyrae stars along their pulsation. This will be used to define methods to detect these type of variables in J-PLUS and J-PLUS. Preliminarly results are presented here.

M33, the Triangulum Galaxy, is a spiral galaxy in the Local Group. Given its brightness and its vicinity with Andromeda Galaxy (M31), it is one of the best studied objects of the Northern hemisphere. In this poster, we present observations carried out with the JAST/T80 at the Observatorio Astrofísico de Javalambre. The extraordinary field of view of this telescope allows us to study the stellar populations of the galaxy with a single observation. Moreover, repeated observations have provided us the possibility to follow a variety of variable stars, among them the nova ASASSN-15th.

To carry out J-PAS survey, the JST/T250 telescope at the Observatorio Astrofósico de Javalambre (OAJ) is equipped with JPCam, a panoramic camera designed to exploit survey capabilities of the telescope. JPCam is a direct imaging instrument designed to work in a fast convergent beam at the telescope’s Cassegrain focus. It is based on state-of-the-art, high efficiency, low noise 9.2k-by-9.2k, 10μm pixel CCDs specially developed by e2v for JPCam. The instrument is equipped with a 1.2Gpixel mosaic of 14 CCDs providing a useful FoV of 4.7 deg2 (67% focal plane coverage) with a plate scale of 0.2267 arcsec/pix. Moreover, JPCam includes 12 auxiliary detectors for auto-guiding and wave front sensing purposes. JPCam is completed with an innovative set of 59 optical filters specifically designed to perform accurate BAO measurements, main science driver of J-PAS.

Classical novae have been studied for over a century but the relation between these explosions and their host systems is still far from complete. In this talk, I review a project aimed at building a statistically significant sample of old nova systems and I analyse the role of future narrow-band surveys in the search for these objects.

Aims: We present the main steps that will be taken to extract Hα emission flux from Javalambre Photometric Local Universe Survey (J-PLUS) photometric data. Methods: For galaxies with z ≲ 0.015, the Hα+[N ii] emission is covered by the J-PLUS narrow-band filter F660. We explore three different methods to extract the Hα + [N ii] flux from J-PLUS photometric data: a combination of a broad-band and a narrow-band filter (r' and F660), two broad-band and a narrow-band filter (r', i' and F660), and an SED-fitting based method using eight photometric points. To test these methodologies, we simulated J-PLUS data from a sample of 7511 SDSS spectra with measured Hα flux. Based on the same sample, we derive two empirical relations to correct the derived Hα+[N ii] flux from dust extinction and [N ii] contamination. Results: We find that the only unbiased method is the SED-fitting based method. The combination of two filters underestimates the measurements of the Hα + [N ii] flux by 22%, while the three filters method are underestimated by 9%. We study the error budget of the SED-fitting based method and find that, in addition to the photometric error, our measurements have a systematic uncertainty of 4.3%. Several sources contribute to this uncertainty: the differences between our measurement procedure and that used to derive the spectroscopic values, the use of simple stellar populations as templates, and the intrinsic errors of the spectra, which were not taken into account. Apart from that, the empirical corrections for dust extinction and [N ii] contamination add an extra uncertainty of 14%. Conclusions: Given the J-PLUS photometric system, the best methodology to extract Hα + [N ii] flux is the SED-fitting based method. Using this method, we are able to recover reliable Hα fluxes for thousands of nearby galaxies in a robust and homogeneous way. Moreover, each stage of the process (emission line flux, dust extinction correction, and [N ii] decontamination) can be decoupled and improved in the future. This method ensures reliable Hα measurements for many studies of galaxy evolution, from the local star formation rate density, to 2D studies in spatially well-resolved galaxies or the study of environmental effects, up to mr' = 21.8 (AB; 3σ detection of Hα+[N ii] emission).

It is widely accepted that large disk galaxies derive from the merger and accretion of many smaller subsystems. However, it is less clear how low-mass spiral galaxies fit into this picture. The best way to answer this question is to study the nearest example of a dwarf spiral galaxy, M 33. We propose to perform a detailed photometric analysis of the resolved and unresolved stellar population of M 33 using data from the Javalambre Photometric Local Universe Survey (J-PLUS). Using a set of 12 broad-, intermediate- and narrow-band filters, J-PLUS will cover a wavelength range between 330-1000 nm, reaching magnitudes of r ~ 22. We will take advantage of the IFU-like capabilities of the survey to determine the properties of the spatially resolved and unresolved components of the galaxy. In particular, we will perform a 2-D analysis of the underlying population as well as a detailed study of M 33 star cluster system. Spectral fitting diagnostics of the resolved and unresolved populations will allow us to determine ages, metallicities and masses of the galactic disk, spheroidal components and cluster system. We will analyze two regions covering a total area of 3.2 deg². One field will be centered on M 33 covering the disk and the outskirts. A second field will cover the line connecting M 33 with M 31 to map the stellar substructure surrounding M 33. This study will provide key insights into the star formation history of low-mass galaxies as well as place M 33 within the context of galaxy formation process.

The Observatorio Astrofisico de Javalambre is equipped with two wide field telescopes with a combination of broad and narrow band filters. The filters of the Javalambre Auxiliary Survey Telescope (80cm diameter) have been designed for stellar classification while the filters of the Javalambre Survey Telescope (2.5m diameter) have been designed for high accuracy determination of photometric redshifts of galaxies. In this article, I explain how the same filter set can also be used to efficiently recover cataclysmic variables and separate them from other objects (like quasars) and even tell their type. The observations to be carried out at the Observatorio Astrofisico de Javalambre will provide the best magnitude limited complete saple of cataclysmic variables to date.

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS; see Benítez et al. 2014) and the Javalambre-Photometric Local Universe Survey (J-PLUS) will be conducted at the brand-new Observatorio Astrofísico de Javalambre (OAJ) in Teruel, Spain. J-PLUS is planned to start by the first half of 2015 while J-PAS first light is expected to happen along 2015. Besides the two main telescopes (with 2.5 m and 80 cm apertures), several smaller-sized facilities are present at the OAJ devoted to site characterization and supporting measurements to be used to calibrate the J-PAS and J-PLUS photometry and to feed up the OAJ's Sequencer with the integrated seeing and the sky transparency. These instruments are: i) an extinction monitor, an 11 " telescope estimating the atmospheric extinction to finally obtain the OAJ extinction curve, which is the initial step to J-PAS overall photometric calibration procedure; ii) an 8 " telescope implementing the Differential Image Motion Monitor (DIMM) technique to obtain the integrated seeing; and iii) an All-Sky Transmission MONitor (ASTMON), a roughly all-sky instrument providing the sky transparency as well as sky brightness and the atmospheric extinction too.

The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55 m telescope of 3 deg field of view, and the JAST/T80, an 83 cm telescope of 2 deg field of view. CEFCA engineering team has been designing the OAJ control system as a global concept to manage, monitor, control and maintain all the observatory systems including not only astronomical subsystems but also infrastructure and other facilities. Three main factors have been considered in the design of a global control system for the robotic OAJ: quality, reliability and efficiency. We propose CIA (Control Integrated Architecture) design and OEE (Overall Equipment Effectiveness) as a key performance indicator in order to improve operation processes, minimizing resources and obtain high cost reduction maintaining quality requirements. Here we present the OAJ robotic control strategy to achieve maximum quality efficiency for the observatory surveys, processes and operations, giving practical examples of our approach.

The Observatorio Astrofísico de Javalambre consists of two main telescopes: JST/T250, a 2.5 m telescope with a FoV of 3 deg, and JAST/T80, a 83 cm with a 2 deg FoV. JST/T250 will be devoted to complete the Javalambre-PAU Astronomical Survey (J-PAS). It is a photometric survey with a system of 54 narrow-band plus 3 broad-band filters covering an area of 8500°^2. The JAST/T80 will perform the J-PLUS survey, covering the same area in a system of 12 filters. This contribution presents the software and hardware architecture designed to store and process the data. The processing pipeline runs daily and it is devoted to correct instrumental signature on the science images, to perform astrometric and photometric calibration, and the computation of individual image catalogs. In a second stage, the pipeline performs the combination of the tile mosaics and the computation of final catalogs. The catalogs are ingested in as Scientific database to be provided to the community. The processing software is connected with a management database to store persistent information about the pipeline operations done on each frame. The processing pipeline is executed in a computing cluster under a batch queuing system. Regarding the storage system, it will combine disk and tape technologies. The disk storage system will have capacity to store the data that is accessed by the pipeline. The tape library will store and archive the raw data and earlier data releases with lower access frequency.

The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys. The main OAJ facilities are two wide-field telescopes: the JST/T250, a 2.55 m telescope with a 3° diameter FoV, and the JAST/T80, a 0.83 m telescope with a 2° diameter FoV. These telescopes are equipped with panoramic cameras that have been designed to exploit the survey capabilities of the OAJ telescopes. T80Cam will be mounted at the JAST/T80 and its large format CCD covers a large fraction of the JAST/T80 FoV with a pixel scale of 0.55"pix⁻¹. The JST/T250 will be equipped with JPCam, a 14-CCD mosaic camera using the new e2v 9k-by-9k, 10 μm pixel detectors, providing a pixel scale of 0.2"pix⁻¹. It is designed to perform the J-PAS, a BAO survey of the northern sky. The J-PAS survey will use 59 filters, 56 narrow-band filters (14.5 nm width) equi-spaced between 350 and 1000 nm plus 3 broad-band filters to achieve unprecedented photometric redshift accuracies for faint galaxies over 8500°² of sky. In this paper, the OAJ first light instrumentation is presented.

White dwarfs are the end state of all main sequence stars less massive than 8M_sun, which means that 98% of all stars will end up as white dwarfs. First and foremost, J-PAS will allow us to discover many new white dwarfs. It will go deeper than SDSS; most of SDSS spectroscopically confirmed white dwarfs have a magnitude below 20.5, while J-PAS will be complete (5σ detections) down to 22.5 in each filter. So we should see white dwarfs 2.5 times farther than SDSS and therefore the total volume will be 2.5³ - 1 = 14.6 times larger. By definition every object in J-PAS will be spectroscopically observed, while in SDSS only chosen objects had their spectra taken, so our white dwarf sample will also be much more complete than SDSS. We expect to increase the total number of white dwarfs from approximately 20,000 to 300,000. Among our goals are the study of the white dwarf luminosity function and the mass distribution.

The Observatorio Astrofísico de Javalambre (OAJ) is a new Spanish astronomical facility particularly designed for carrying out large sky surveys. The OAJ is mainly motivated by the development of J-PAS, the Javalambre- PAU Astrophysical Survey, an unprecedented astronomical survey that aims to observe 8500 deg² of the sky with a set of 54 optical contiguous narrow-band filters (FWHM ~14 nm) and 5 mid and broad-band ones. J-PAS will provide a low resolution spectrum (R ~ 50) for every pixel of the Northern sky down to AB~22:5 - 23:5 per square arcsecond (at 5 σ level), depending on the narrow-band filter, and ~ 2 magnitudes deeper for the redder broad-band filters. The main telescope at the OAJ is the Javalambre Survey Telescope (JST/T250), an innovative Ritchey-Chrétien, alt-azimuthal, large-etendue telescope with a primary mirror diameter of 2.55m and 3 deg (diameter) FoV. The JST/T250 is the telescope devoted to conduct J-PAS with JPCam, a panoramic camera of 4.7 deg² FoV and a mosaic of 14 large format CCDs that, overall, amounts to 1.2 Gpix. The second largest telescope at the OAJ is the Javalambre Auxiliary Survey Telescope (JAST/T80), a Ritchey-Chrétien, German-equatorial telescope of 82 cm primary mirror and 2 deg FoV, whose main goal is to perform J-PLUS, the Javalambre Photometric Local Universe Survey. J-PLUS will cover the same sky area of J-PAS using the panoramic camera T80Cam with 12 filters in the optical range, which are specifically defined to perform the photometric calibration of J-PAS. The OAJ project officially started in mid 2010. Four years later, the OAJ is mostly completed and the first OAJ operations have already started. The civil work and engineering installations are finished, including the telescope buildings and the domes. JAST/T80 is at the OAJ undertaking commissioning tasks, and JST/T250 is in AIV phase at the OAJ. Related astronomical subsystems like the seeing and atmospheric extinction monitors and the all-sky camera are fully operative. This paper aims to present a brief description and status of the OAJ main installations, telescopes and cameras. The current development and operation plan of the OAJ in terms of staffing organization, resources, observation scheduling, and data archiving, is also described.

The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view. CEFCA engineering team has been designing the OAJ control system as a global concept to manage, monitor, control and maintain all the observatory systems including not only astronomical subsystems but also infrastructure and other facilities. In order to provide quality, reliability and efficiency, the OAJ control system (OCS) design is based on CIA (Control Integrated Architecture) and OEE (Overall Equipment Effectiveness) as a key to improve day and night operation processes. The OCS goes from low level hardware layer including IOs connected directly to sensors and actuators deployed around the whole observatory systems, including telescopes and astronomical instrumentation, up to the high level software layer as a tool to perform efficiently observatory operations. We will give an overview of the OAJ control system design and implementation from an engineering point of view, giving details of the design criteria, technology, architecture, standards, functional blocks, model structure, development, deployment, goals, report about the actual status and next steps.

The Observatorio Astrofísico de Javalambre have two main telescopes: JST/T250, a 2.5m 3deg FoV and JAST/T80 with 2deg FoV. From OAJ two surveys of 8500 square degrees will be carried out. J-PAS using 54 narrow and several broad band filters and J-PLUS using 12 filters. Both surveys will produce ~2.5 PB of data. This contribution presents the software and hardware architecture to store, process and publish the data. Results about pipeline and hardware performance with data collected during the first months of JAST/T80 operation will be presented.

The Observatorio Astrofísico de Javalambre in Spain is a new astronomical facility particularly conceived for carrying out large sky surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view. The most immediate objective of the two telescopes for the next years is carrying out two unique photometric surveys of several thousands square degrees, J-PAS[9][14][16] and J-PLUS [14][16], each of them with a wide range of scientific applications, like e.g. large structure cosmology and Dark Energy, galaxy evolution, supernovae, Milky Way structure, exoplanets, among many others. To do that, JST and JAST will be equipped with panoramic cameras under development within the J-PAS collaboration, JPCam and T80Cam respectively, which make use of large format (~ 10k x 10k) CCDs covering the entire focal plane. This paper describes in detail the engineering development of the overall facilities and infrastructures for the robotic observatory and a global overview of current status and future actions to perform from engineering point of view.

The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a new astronomical facility dedicated to mapping the observable Universe in 59 colors, and will produce high-quality images and an unique spectral resolution over the 8000 deg². It will consist of two telescopes. One of 2.5-m (J-PAS) and another of 0.8-m (J-PLUS, mainly for calibrations). The former will have a dedicated 1.2-G pixel survey camera (containing an array of 14 CCDs) with a FoV of 5 deg^2. It is planned to take 4-5 years and is expected to map the above area to a 5σ magnitude depth for point sources equivalent to i˜23.3 over an aperture of 2 arcsec². The J-PAS filter system consists of 54 contiguous narrow band filters of 100-Å FWHM, from 3,500 to 10,000Å. To those filters 2 broad-band ones will be at the extremes, UV and IR, plus 3 SDSS g, r, and i filters. J-PLUS, on the other hand, comprise 12 filters, including g, r, i and z SDSS ones. Though about 2,500 PNe (confirmed spectroscopically) are known in the Galaxy, only about 20 objects have been identified as halo PNe. They were found from their location, kinematics and chemistry. Halo PNe are able to reveal precious information for the study of low- and intermediate-mass star evolution and the early chemical conditions of the Galaxy. The characteristic low continuum and intense line emissions of PNe make them good objects to be searched for by J-PAS. For instance, the halo PNe BoBn 1, DdDm 1 and PS 1, located somewhere between 11 and 24 kpc from the Sun, have B magnitudes of 16, 14 and 13.4, respectively. Such values are easily encompassed by J-PAS, given the typical limit magnitude of the survey. Because of the low number of halo PNe detected so far, we are developing tools to find these objects by using J-PAS/J-PLUS, and planning a follow-up study for any possible candidate identified by the survey. Color magnitudes diagram able to separate PNe from other strong line emission objects are being explored by the group and results are discussed in this contribution.

There are many ways to solve the challenging problem of making a high performance robotic observatory from scratch. The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located in the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys. The OAJ control system has been designed from a global point of view including astronomical subsystems as well as infrastructures and other facilities. Three main factors have been considered in the design of a global control system for the robotic OAJ: quality, reliability and efficiency. We propose CIA (Control Integrated Architecture) design and OEE (Overall Equipment Effectiveness) as a key performance indicator in order to improve operation processes, minimizing resources and obtaining high cost reduction whilst maintaining quality requirements. The OAJ subsystems considered for the control integrated architecture are the following: two wide-field telescopes and their instrumentation, active optics subsystems, facilities for sky quality monitoring (seeing, extinction, sky background, sky brightness, cloud distribution, meteorological station), domes and several infrastructure facilities such as water supply, glycol water, water treatment plant, air conditioning, compressed air, LN2 plant, illumination, surveillance, access control, fire suppression, electrical generators, electrical distribution, electrical consumption, communication network, Uninterruptible Power Supply and two main control rooms, one at the OAJ and the other remotely located in Teruel, 40km from the observatory, connected through a microwave radio-link. This paper presents the OAJ strategy in control design to achieve maximum quality efficiency for the observatory processes and operations, giving practical examples of our approach.