An Exploratory Analysis of New Large Gaia-informed Quasar Samples in SDSS-V
Year: 2026
Type: article
Abstract: Quasars are extremely luminous objects that provide insights into the physics and evolution of supermassive black holes (SMBHs) and their accretion flows, galaxy evolution, and even cosmology. In this study, we present an exploratory study based on the ongoing fifth generation of the Sloan Digital Sky Survey (SDSS-V) and its unique dual-hemisphere, wide-field, and multiobject spectroscopic capabilities, with the aim of creating a comprehensive, all-sky quasar sample. The targets were selected through two novel methods, Gaia–unWISE AGN (GUA) and Skewt_QSO, that rely primarily on data from the Wide-field Infrared Survey Explorer (WISE) and Gaia, aiming to address gaps in previous large quasar samples. Our sample includes over 250,000 spectroscopically confirmed quasars reaching to z ∼ 5, with tens of thousands of newly identified quasars in the southern hemisphere. The selection methods are highly pure, with well over 80% of the spectra collected being genuine quasars; the main contaminants are M-type stars. The detailed spectral decomposition procedure we employed shows that the quasars in the sample span a wide range of luminosities ( L bol ∼ 10 44 −10 48 erg s −1 ), SMBH masses ( M BH ∼ 10 6 −10 10 M ⊙ ), and accretion rates ( L / L Edd ∼ 0.01−1). The distributions of these properties are consistent with those of previous quasar catalogs, which are based on past generations of SDSS, once we account for potential selection biases related to the various survey depths. Our findings confirm that novel selection methods based on optical+infrared colors and/or astrometry can yield a large, high-purity quasar sample over wide sky areas, including in cases where more nuanced multiband photometry and/or multiwavelength data in the X-ray or radio are not available. This SDSS-V sample, which is expected to grow in the near future, establishes a robust reference for future southern (time-domain) surveys, while enhancing and complementing our understanding of quasar demographics and SMBH evolution.
Source: The Astrophysical Journal
Authors: Shir Aviram, Benny Trakhtenbrot, Tom Dwelly, Scott F. Anderson, Sean Morrison, Michael Eracleous, Yue Shen, Mara Salvato, Donald P. Schneider, Roberto J. Assef, Catarina Aydar, Franz E. Bauer, W. N. Brandt, Joel R. Brownstein, Johannes Buchner, Jeremy Darling, José G. Fernández-Trincado, Patrick B. Hall, Dong-Woo Kim, Anton M. Koekemoer, Stephanie LaMassa, Andrea Merloni, Claudio Ricci, Qian Yang, Grisha Zeltyn
Institutions: Tel Aviv University, Max Planck Institute for Extraterrestrial Physics, University of Washington, University of Illinois Urbana-Champaign, Pennsylvania State University, Universidad Diego Portales, Excellence Cluster Origins, University of Tarapacá, University of Utah, Universidad Bernardo O'Higgins, York University, Center for Astrophysics Harvard & Smithsonian, Space Telescope Science Institute, University of Geneva, Peking University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, Alfred P. Sloan Foundation, Yale University, Carnegie Institution of Washington, Ohio State University, California Institute of Technology, Harvard University, Johns Hopkins University, New Mexico State University, Space Telescope Science Institute, Flatiron Health, European Commission, Deutsche Forschungsgemeinschaft, École Polytechnique Fédérale de Lausanne, University of Toronto, Israel Science Foundation, Universidad Nacional Autónoma de México, Yunnan University, Nanjing University, Pontificia Universidad Católica de Chile, China National Textile and Apparel Council, Leibniz-Institut für Astrophysik Potsdam, Agencia Nacional de Investigación y Desarrollo, Max-Planck-Institut für Astronomie, University of Illinois at Urbana-Champaign, University of Colorado Boulder, Smithsonian Astrophysical Observatory, Leibniz-Gemeinschaft, National Astronomical Observatories, Chinese Academy of Sciences
Awards: AGNS THROUGH COSMIC TIME HOT DUST OBSCURED GALAXIES AND THE RUBIN LSST, Understanding the Stellar Mass and Environmental Dependences of Cosmic Black-Hole Growth, G2724668986, G2808433674, RAPID: Fast Mobility Particle Size Measurements during the 4th Fire Lab at Missoula Experiment (FLAME IV) Study, G4066435496, EXC 2094: ORIGINS: Vom Ursprung des Universums bis zu den ersten Bausteinen des Lebens, SPECTRO-TEMPORAL STUDIES OF AGN POPULATIONS, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA)
OpenAlex ID: W7171971946