Publicaciones: Científicas

Publicaciones: Científicas

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.

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Cataclysmic Variables (CVs) are binaries in which a WD accretes from a lowmass companion. 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 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.
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.

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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.

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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.

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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.

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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.

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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 (

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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).

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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.

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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.

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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.

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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.

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