ANDREI, A. H.; ASSAFIN, M.; BARACHE, C.; BOUQUILLON, S.; BOURDA, G.; CAMARGO, J. I. B.; LE CAMPION, J.-F.; CHARLOT, P.; GONTIER, A.-M.; LAMBERT, S.; OSÓRIO, J. J. Pereira; DA SILVA NETO, D. N.; SOUCHAY, J.; MARTINS, R. Vieira

doi:10.1017/S1743921308019212

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ANDREI, A. H.
Systèmes de Référence Temps Espace [SYRTE]

ASSAFIN, M.

BARACHE, C.
Systèmes de Référence Temps Espace [SYRTE]

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Proceedings of the International Astronomical Union, IAU Symposium, Symposium - 2008IAUS..248..260A, Proceedings of the International Astronomical Union, IAU Symposium, Symposium - 2008IAUS..248..260A, A Giant Step: from Milli- to Micro-arcsecond Astrometry, 2007, Shanghai. 2008, vol. 248, p. 260-261

Cambridge University Press

Résumé en anglais

Gaia photometric capabilities should distinguish quasars to a high degree of certainty. With this, they should also be able to deliver a clean sample of quasars with a negligible trace of stellar contaminants. However, a purely photometric sample could miss a non negligible percentage of ICRF sources counterparts - and this interface is required to align with the ICRS and de-rotate the GCRF (Gaia Celestial Reference Frame), on grounds of continuity. To prepare a minimum clean sample forming the initial quasar catalogue for the Gaia mission, an all sky ensemble was formed containing 128,257 candidates. Among them there is at least one redshift determination for 98.75%, and at least one magnitude determination for 99.20% of the targets. The sources were collected from different optical and radio lists. We analyze the redshift, magnitude, and color distributions, their relationships, as well as their degree of completeness. Complementary, the candidate sources enable to form an optical representation of the ICRS from first principles, namely, kinematically non-rotating with respect to the ensemble of distant extragalactic objects, aligned to the mean equator and dynamical equinox of J2000, and realized by a list of adopted coordinates of extragalactic sources.< Réduire

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reference systems

quasars: general

astronomical data bases: miscellaneous

astrometry

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A Gaia oriented analysis of a large sample of quasars

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