RT journal article
T1 Gaia Data Release 3: The extragalactic content
A1 Bailer-Jones, C.A.L.
A1 Teyssier, D.
A1 Delchambre, L.
A1 Ducourant, C.
A1 Garabato, D.
A1 Berihuete Macías, Angel
A2 Estadística e Investigación Operativa
K1 surveys
K1 galaxies: general
K1 quasars: general
AB The Gaia Galactic survey mission is designed and optimized to obtain astrometry, photometry, and spectroscopy of nearly two billion stars in ourGalaxy. Yet as an all-sky multi-epoch survey, Gaia also observes several million extragalactic objects down to a magnitude of G ∼ 21 mag. Dueto the nature of the Gaia onboard-selection algorithms, these are mostly point-source-like objects. Using data provided by the satellite, we haveidentified quasar and galaxy candidates via supervised machine learning methods, and estimate their redshifts using the low resolution BP/RPspectra. We further characterise the surface brightness profiles of host galaxies of quasars and of galaxies from pre-defined input lists. Here wegive an overview of the processing of extragalactic objects, describe the data products in Gaia DR3, and analyse their properties. Two integratedtables contain the main results for a high completeness, but low purity (50−70%), set of 6.6 million candidate quasars and 4.8 million candidategalaxies. We provide queries that select purer sub-samples of these containing 1.9 million probable quasars and 2.9 million probable galaxies (both∼95% purity). We also use high quality BP/RP spectra of 43 thousand high probability quasars over the redshift range 0.05−4.36 to construct acomposite quasar spectrum spanning restframe wavelengths from 72−1000 nm.
PB EDP Sciences
SN 1432-0746
YR 2023
FD 2023
LK http://hdl.handle.net/10498/31795
UL http://hdl.handle.net/10498/31795
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026