Gaia Data Release 2. The celestial reference frame (Gaia-CRF2)

0495379 - ASÚ 2019 RIV FR eng J - Journal Article
Mignard, F. - Klioner, S. - Lindegren, L. - Hernandez, J. - Bastian, U. - Bombrun, A. - Hobbs, D. - Lammers, U. - Michalik, D. - Koubský, Pavel - Votruba, Viktor … Total 451 authors
Gaia Data Release 2. The celestial reference frame (Gaia-CRF2).
Astronomy & Astrophysics. Roč. 616, August (2018), č. článku A14. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:67985815
Keywords : astrometry * reference systems * catalogs
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.209, year: 2018

Gaia-CRF2 consists of the positions of a sample of 556 869 sources in Gaia DR2, obtained from a positional cross-match with the ICRF3-prototype and AllWISE AGN catalogues. The sample constitutes a clean, dense, and homogeneous set of extragalactic point sources in the magnitude range G similar or equal to 16 to 21 mag with accurately known optical positions. The median positional uncertainty is 0.12 mas for G < 18 mag and 0.5 mas at G = 20 mag. Large-scale systematics are estimated to be in the range 20 to 30 mu as. The accuracy claims are supported by the parallaxes and proper motions of the quasars in Gaia DR2. The optical positions for a subset of 2820 sources in common with the ICRF3-prototype show very good overall agreement with the radio positions, but several tens of sources have significantly discrepant positions.

Permanent Link: http://hdl.handle.net/11104/0288369