Gaia DR3: Apsis III -- Non-stellar content and source classification
Abstract
Context. As part of the third Gaia data release, we present the contributions of the non-stellar and classification modules from the eighth coordination unit (CU8) of the Data Processing and Analysis Consortium, which is responsible for the determination of source astrophysical parameters using Gaia data. This is the third in a series of three papers describing the work done within CU8 for this release. Aims. For each of the five relevant modules from CU8, we summarise their objectives, the methods they employ, their performance, and the results they produce for Gaia DR3. We further advise how to use these data products and highlight some limitations. Methods. The Discrete Source Classifier (DSC) module provides classification probabilities associated with five types of sources: quasars, galaxies, stars, white dwarfs, and physical binary stars. A subset of these sources are processed by the Outlier Analysis (OA) module, which performs an unsupervised clustering analysis, and then associates labels with the clusters to complement the DSC classification. The Quasi Stellar Object Classifier (QSOC) and the Unresolved Galaxy Classifier (UGC) determine the redshifts of the sources classified as quasar and galaxy by the DSC module. Finally, the Total Galactic Extinction (TGE) module uses the extinctions of individual stars determined by another CU8 module to determine the asymptotic extinction along all lines of sight for Galactic latitudes |b| > 5 deg. Results. Gaia DR3 includes 1591 million sources with DSC classifications; 56 million sources to which the OA clustering is applied; 1.4 million sources with redshift estimates from UGC; 6.4 million sources with QSOC redshift; and 3.1 million level 9 HEALPixes of size 0.013 squared degree, where the extinction is evaluated by TGE.
Keywords
Cite
@article{arxiv.2206.06710,
title = {Gaia DR3: Apsis III -- Non-stellar content and source classification},
author = {L. Delchambre and C. A. L. Bailer-Jones and I. Bellas-Velidis and R. Drimmel and D. Garabato and R. Carballo and D. Hatzidimitriou and D. J. Marshall and R. Andrae and C. Dafonte and E. Livanou and M. Fouesneau and E. L. Licata and H. E. P. Lindstrom and M. Manteiga and C. Robin and A. Silvelo and A. Abreu Aramburu and M. A. Alvarez and J. Bakker and A. Bijaoui and N. Brouillet and E. Brugaletta and A. Burlacu and L. Casamiquela and L. Chaoul and A. Chiavassa and G. Contursi and W. J. Cooper and O. L. Creevey and A. Dapergolas and P. de Laverny and C. Demouchy and T. E. Dharmawardena and B. Edvardsson and Y. Fremat and P. Garcia-Lario and M. Garcia-Torres and A. Gavel and A. Gomez and I. Gonzalez-Santamaria and U. Heiter and A. Jean-Antoine Piccolo and M. Kontizas and G. Kordopatis and A. J. Korn and A. C. Lanzafame and Y. Lebreton and A. Lobel and A. Lorca and A. Magdaleno Romeo and F. Marocco and N. Mary and C. Nicolas and C. Ordenovic and F. Pailler and P. A. Palicio and L. Pallas-Quintela and C. Panem and B. Pichon and E. Poggio and A. Recio-Blanco and F. Riclet and J. Rybizki and R. Santovena and L. M. Sarro and M. S. Schultheis and M. Segol and I. Slezak and R. L. Smart and R. Sordo and C. Soubiran and M. Suveges and F. Thevenin and G. Torralba Elipe and A. Ulla and E. Utrilla and A. Vallenari and E. van Dillen and H. Zhao and J. Zorec},
journal= {arXiv preprint arXiv:2206.06710},
year = {2023}
}
Comments
Accepted by A&A. 36 pages, 29 figures, 9 tables