13 research outputs found

    The southern photometric local universe survey (S-PLUS): Improved SEDs, morphologies, and redshifts with 12 optical filters

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    The Southern Photometric Local Universe Survey (S-PLUS) is imaging ~9300 deg2 of the celestial sphere in 12 optical bands using a dedicated 0.8mrobotic telescope, the T80-South, at the Cerro Tololo Inter-american Observatory, Chile. The telescope is equipped with a 9.2k × 9.2k e2v detector with 10 ÎŒm pixels, resulting in a field of view of 2 deg2 with a plate scale of 0.55 arcsec pixel-1. The survey consists of four main subfields, which include two non-contiguous fields at high Galactic latitudes (|b| > 30° , 8000 deg2) and two areas of the Galactic Disc and Bulge (for an additional 1300 deg2). S-PLUS uses the Javalambre 12-band magnitude system, which includes the 5 ugriz broad-band filters and 7 narrow-band filters centred on prominent stellar spectral features: the Balmer jump/[OII], Ca H + K, Hd, G band, Mg b triplet, Hα, and the Ca triplet. S-PLUS delivers accurate photometric redshifts (ÎŽz/(1 + z) = 0.02 or better) for galaxies with r < 19.7 AB mag and z < 0.4, thus producing a 3D map of the local Universe over a volume of more than 1 (Gpc/h)3. The final S-PLUS catalogue will also enable the study of star formation and stellar populations in and around the Milky Way and nearby galaxies, as well as searches for quasars, variable sources, and low-metallicity stars. In this paper we introduce the main characteristics of the survey, illustrated with science verification data highlighting the unique capabilities of S-PLUS. We also present the first public data release of ~336 deg2 of the Stripe 82 area, in 12 bands, to a limiting magnitude of r = 21, available at datalab.noao.edu/splus.Fil: De Oliveira, C. Mendes. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Ribeiro, T.. Universidade Federal de Sergipe; Brasil. National Optical Astronomy Observatory; Estados UnidosFil: Schoenell, W.. Universidade Federal do Rio Grande do Sul; BrasilFil: Kanaan, A.. Universidade Federal de Santa Catarina; BrasilFil: Overzier, R.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; Brasil. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; BrasilFil: Molino, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Sampedro, L.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Coelho, P.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Barbosa, C.E.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Cortesi, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Costa Duarte, M.V.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Herpich, F.R.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal de Santa Catarina; BrasilFil: Hernandez Jimenez, J.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Placco, V.M.. University of Notre Dame; Estados Unidos. JINA Center for the Evolution of the Elements ; Estados UnidosFil: Xavier, H.S.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Abramo, L.R.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Saito, R.K.. Universidade Federal de Santa Catarina; BrasilFil: Chies Santos, A.L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Ederoclite, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; Brasil. Centro de Estudios de FĂ­sica del Cosmo de Aragon; EspañaFil: De Oliveira, R. Lopes. Universidade Federal de Sergipe; Brasil. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; Brasil. University of Maryland; Estados UnidosFil: Goncalves, D.R.. Universidade Federal do Rio de Janeiro; BrasilFil: Akras, S.. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Almeida, L.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal do Rio Grande do Norte; BrasilFil: Almeida Fernandes, F.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Beers, T.C.. University of Notre Dame; Estados Unidos. JINA Center for the Evolution of the Elements ; Estados UnidosFil: Bonatto, C.. Universidade Federal do Rio Grande do Sul; BrasilFil: Bonoli, S.. Centro de Estudios de FĂ­sica del Cosmo de Aragon; EspañaFil: Cypriano, E.S.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Vinicius Lima, E.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂ­sica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de AstrofĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias AstronĂłmicas y GeofĂ­sicas. Instituto de AstrofĂ­sica La Plata; Argentin

    J-PLUS: The javalambre photometric local universe survey

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    ABSTRACT: TheJavalambrePhotometric Local UniverseSurvey (J-PLUS )isanongoing 12-band photometricopticalsurvey, observingthousands of squaredegrees of theNorthernHemispherefromthededicated JAST/T80 telescope at the Observatorio AstrofĂ­sico de Javalambre (OAJ). The T80Cam is a camera with a field of view of 2 deg2 mountedon a telescopewith a diameter of 83 cm, and isequippedwith a uniquesystem of filtersspanningtheentireopticalrange (3500–10 000 Å). Thisfiltersystemis a combination of broad-, medium-, and narrow-band filters, optimallydesigned to extracttherest-framespectralfeatures (the 3700–4000 Å Balmer break region, HÎŽ, Ca H+K, the G band, and the Mg b and Ca triplets) that are key to characterizingstellartypes and delivering a low-resolutionphotospectrumforeach pixel of theobservedsky. With a typicaldepth of AB ∌21.25 mag per band, thisfilter set thusallowsforanunbiased and accuratecharacterization of thestellarpopulation in our Galaxy, itprovidesanunprecedented 2D photospectralinformationforall resolved galaxies in the local Universe, as well as accuratephoto-z estimates (at the ή z/(1 + z)∌0.005–0.03 precisionlevel) formoderatelybright (up to r ∌ 20 mag) extragalacticsources. Whilesomenarrow-band filters are designedforthestudy of particular emissionfeatures ([O II]/λ3727, Hα/λ6563) up to z < 0.017, theyalsoprovidewell-definedwindowsfortheanalysis of otheremissionlines at higherredshifts. As a result, J-PLUS has thepotential to contribute to a widerange of fields in Astrophysics, both in thenearbyUniverse (MilkyWaystructure, globular clusters, 2D IFU-likestudies, stellarpopulations of nearby and moderate-redshiftgalaxies, clusters of galaxies) and at highredshifts (emission-line galaxies at z ≈ 0.77, 2.2, and 4.4, quasi-stellarobjects, etc.). Withthispaper, wereleasethefirst∌1000 deg2 of J-PLUS data, containingabout 4.3 millionstars and 3.0 milliongalaxies at r <  21mag. With a goal of 8500 deg2 forthe total J-PLUS footprint, thesenumbers are expected to rise to about 35 millionstars and 24 milliongalaxiesbytheend of thesurvey.Funding for the J-PLUS Project has been provided by the Governments of Spain and AragĂłn through the Fondo de Inversiones de Teruel, the Spanish Ministry of Economy and Competitiveness (MINECO; under grants AYA2017-86274-P, AYA2016-77846-P, AYA2016-77237-C3-1-P, AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, AGAUR grant SGR-661/2017, and ICTS-2009-14), and European FEDER funding (FCDD10-4E-867, FCDD13-4E-2685

    Assessing the photometric redshift precision of the S-PLUS survey: The Stripe-82 as a test-case

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    IndexaciĂłn ScopusIn this paper we present a thorough discussion about the photometric redshift (photo-z) performance of the Southern Photometric Local Universe Survey (S-PLUS). This survey combines a seven narrow +5 broad passband filter system, with a typical photometric-depth of r ∌ 21 AB. For this exercise, we utilize the Data Release 1 (DR1), corresponding to 336 deg2 from the Stripe-82 region. We rely on the BPZ2 code to compute our estimates, using a new library of SED models, which includes additional templates for quiescent galaxies. When compared to a spectroscopic redshift control sample of ∌100 k galaxies, we find a precision of σz <0.8 per cent, <2.0 per cent, or <3.0 per cent for galaxies with magnitudes r < 17, <19, and <21, respectively. A precision of 0.6 per cent is attained for galaxies with the highest Odds values. These estimates have a negligible bias and a fraction of catastrophic outliers inferior to 1 per cent. We identify a redshift window (i.e. 0.26 < z < 0.32) where our estimates double their precision, due to the simultaneous detection of two emission lines in two distinct narrow bands; representing a window opportunity to conduct statistical studies such as luminosity functions. We forecast a total of ∌2 M, ∌16 M and ∌32 M galaxies in the S-PLUS survey with a photo-z precision of σz <1.0 per cent, <2.0 per cent, and <2.5 per cent after observing 8000 deg2. We also derive redshift probability density functions, proving their reliability encoding redshift uncertainties and their potential recovering the n(z) of galaxies at z < 0.4, with an unprecedented precision for a photometric survey in the Southern hemisphere. © 2020 The Author(s)https://academic-oup-com.recursosbiblioteca.unab.cl/mnras/article/499/3/3884/585601

    The case for electron re-acceleration at galaxy cluster shocks

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    On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-sized radio sources have been found1,2 . Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach-number shocks generated by cluster–cluster merger events 3 . A long-standing problem is how low-Mach-number shocks can accelerate electrons so efficiently to explain the observed radio relics. Here, we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411–3412 by combining radio, X-ray and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. It also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.Galaxie

    J-PLUS: Morphological star/galaxy classification by PDF analysis

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    International audienceAims. Our goal is to morphologically classify the sources identified in the images of the J-PLUS early data release (EDR) as compact (stars) or extended (galaxies) using a dedicated Bayesian classifier.Methods. J-PLUS sources exhibit two distinct populations in the r-band magnitude versus 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 objects. The derived model and the number density prior based on J-PLUS EDR data were used to estimate the Bayesian probability that a source is a star or a galaxy. This procedure was applied pointing-by-pointing to account for varying observing conditions and sky positions. Finally, we combined the morphological information from the g, r, and i broad bands in order to improve the classification of low signal-to-noise sources.Results. The derived probabilities are used to compute the pointing-by-pointing number counts of stars and galaxies. The former increases as we approach 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.Conclusions. We implement a morphological star/galaxy classifier based on probability distribution function 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 150 thousand stars and 101 thousand 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 12 photometric bands.Key words: methods: data analysis / Galaxy: stellar content / galaxies: statistic

    Horizons: Nuclear Astrophysics in the 2020s and Beyond

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    Nuclear Astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities
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