Paper published in a book (Scientific congresses and symposiums)
Quasars with Gaia: Identification and Astrophysical Parameters
Claeskens, Jean-François; Smette, A.; Surdej, Jean
2005In Turon, C.; O'Flaherty, K. S.; Perryman, M. A. C. (Eds.) Proceedings of the Gaia Symposium "The Three-Dimensional Universe with Gaia" (ESA SP-576)
 

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Keywords :
Quasars; Astrophysical Parameters; Photometry
Abstract :
[en] Gaia will provide astrometric and photometric observations for about 500 000 quasars distributed over the whole sky. The latter would constitute an isotropic grid of fixed sources perfectly suited to determine the referential frame. However, they must first be properly identified among stars, whose population is about 2000 times larger. Using broad and medium band photometry, we first compare the efficiency of two analysis methods (Ï 2 fitting and Artificial Neural Networks, ANNs) to produce the QSO catalogue with the lowest amount of contamination by stars. We then investigate whether the Gaia photometry could also provide precise values of the QSO astrophysical parameters (APs, like the redshift, the continuum slope, the emission line strength and possibly the extinction). To reach that purpose, we also compare the performances of the Spectral Principal Component Analysis (SPCA) with those of the Ï 2 fitting and ANN analysis.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Claeskens, Jean-François 
Smette, A.
Surdej, Jean  ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Language :
English
Title :
Quasars with Gaia: Identification and Astrophysical Parameters
Publication date :
01 January 2005
Event organizer :
Observatoire de Paris-Meudon
Event place :
Paris-Meudon, France
Event date :
4-7 October 2004
By request :
Yes
Audience :
International
Main work title :
Proceedings of the Gaia Symposium "The Three-Dimensional Universe with Gaia" (ESA SP-576)
Editor :
Turon, C.
O'Flaherty, K. S.
Perryman, M. A. C.
Pages :
667-673
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since 13 December 2009

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