Volume 494, Number 2, February I 2009
|Page(s)||799 - 815|
|Section||Catalogs and data|
|Published online||04 December 2008|
The construction of the large quasar astrometric catalogue (LQAC) *
Observatoire de Paris, Systèmes de Référence Temps Espace (SYRTE), CNRS/UMR 8630, Paris, France e-mail: Jean.Souchay@obspm.fr
2 Observatório Nacional/MCT and Observatório do Valongo/UFRJ, Rio de Janeiro, Brasil
3 Technische Universität Dresden, Institut für Planetare Geodäsie, Lohrmann Observatorium, Dresden, Germany
4 Bureau International des Poids et Mesures, Sèvres, France
Accepted: 3 November 2008
Context. The very large and increasing number of quasars reckoned from various sky surveys leads to a large quantity of data which brings various and inhomogeneous information in the fields of astrometry, photometry, radioastronomy and spectroscopy.
Aims. In this paper, we describe our work that aims to make available a general compilation of the largest number of recorded quasars obtained from all the available catalogues, with their best position estimates, and providing physical information at both optical and radio wavelengths. Thus, we construct a catalogue compilation designated Large Quasar Astrometric Catalogue (LQAC) giving coordinates, multiband photometry, radio fluxes, redshift, luminosity distances and absolute magnitudes.
Methods. We gather the 12 largest quasar catalogues (4 from radio interferometry programs, 8 from optical surveys), and we carry out systematic cross-identifications of the objects. Information concerning u, b, v, g, r, i, z, J, K photometry as well as redshift and radio fluxes at 1.4 GHz, 2.3 GHz, 5.0 GHz, 8.4 GHz and 24 GH are given when available. A small proportion of remaining objects, not present in the 12 catalogues and included in the Véron-Cetty & Véron quasar catalogues, are added to the compilation.
Results. The LQAC contains 113 666 quasars. We discuss the external homogeneity of the data by comparing the coordinates, the redshifts and the magnitudes of objects belonging to different catalogues. We use up-to-date cosmological parameters as well as recent models for galactic extinction and K-correction in order to evaluate the absolute magnitudes of the objects.
Key words: reference systems / astrometry / quasars: general / catalogs
© ESO, 2009
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.