Gaia Data Release 3

Validating the classification of variable young stellar object candidates^⋆

¹ Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly Thege Miklós Út 15-17, 1121 Budapest, Hungary
² CSFK, MTA Centre of Excellence, Budapest, Konkoly Thege Miklós Út 15-17 1121, Hungary
e-mail: marton.gabor@csfk.org
³ ELTE Eötvös Loránd University, Institute of Physics, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
⁴ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
⁵ Department of Astronomy, University of Geneva, Chemin d’Ecogia 16, 1290 Versoix, Switzerland
⁶ Department of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, Switzerland
⁷ RHEA for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
⁸ Sednai Sàrl, Geneva, Switzerland
⁹ Université de Caen Normandie, Côte de Nacre Boulevard Maréchal Juin, 14032 Caen, France
¹⁰ European Space Agency (ESA), European Space Astronomy Centre (ESAC), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain

Received: 24 May 2022
Accepted: 18 December 2022

Abstract

Context. The Gaia third Data Release (DR3) presents the first catalogue of full-sky variable young stellar object (YSO) candidates observed by the Gaia space telescope during the initial 34 months of science operations.

Aims. Numerous types of variable stars were classified using photometric data collected by Gaia. One of the new classes presented in the Gaia DR3 is the class of YSOs showing brightness variability. We analysed 79 375 sources classified as YSO candidates in order to validate their young nature and investigate the completeness and purity of the sample.

Methods. We cross-matched the Gaia DR3 YSO sample with numerous catalogues from the literature, including YSO catalogues based on optical and infrared data, as well as catalogues of extragalactic sources and Galactic variable stars. YSO catalogues were used to quantify the completeness of the Gaia DR3 YSO sample, while others were inspected to calculate the contamination.

Results. Among the 79 375 potential YSO candidates published in the Gaia DR3 variable star catalogue, the majority of these objects are distributed along the line of sight of well-known star forming regions and the Galactic midplane. We find that the upper limit of contamination is 26.7%, depending on the external catalogue used for the estimation, but find an average of ∼10% in general, while the completeness is at the percent level, taking into account that the Gaia DR3 YSO sample is based on sources that showed significant variability during the data-collection period. The number of sources in our sample that had not previously been catalogued as YSO candidates is ∼40 000 objects.