The Unresolved Galaxies with Gaia

M. Kontizas; I. Bellas-Velidis; B. Rocca-Volmerange; E. Kontizas; P. Tsalmantza; E. Livanou; A. Dapergolas; A. Karampelas

doi:10.1051/eas/1045057

All issues

Volume 45 (2010)

EAS Publications Series, 45 (2010) 337-342

Abstract

Issue		EAS Publications Series Volume 45, 2010 GAIA: At the Frontiers of Astrometry


Page(s)		337 - 342
DOI		https://doi.org/10.1051/eas/1045057
Published online		15 February 2011

GAIA: At the Frontiers of Astrometry
C. Turon, F. Meynadier and F. Arenou (eds)
EAS Publications Series, 45 (2010) 337-342

The Unresolved Galaxies with Gaia

M. Kontizas¹, I. Bellas-Velidis², B. Rocca-Volmerange³^,4, E. Kontizas², P. Tsalmantza⁵, E. Livanou¹, A. Dapergolas² and A. Karampelas¹

¹ National and Kapodistrian University of Athens, Faculty of Physics, Athens, Greece
² National Observatory of Athens, Athens, Greece
³ Institut d’Astrophysique de Paris, 98bis Bd. Arago, 75014 Paris, France
⁴ Université de Paris-Sud XI, I.A.S., 91405 Orsay Cedex, France
⁵ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

Abstract

Classification and parametrization of unresolved galaxies to be detected by Gaia is the goal of our contribution to DPAC/CU8. Gaia will observe more than several times 10⁶ unresolved galaxies seen almost as point sources. For the classification and parametrization of these sources we have undertaken the following tasks: a) providing libraries of synthetic galaxy spectra (produced under the PÉGASE.2 code of galaxy evolution) and a semi-empirical library using observed galaxy spectra from SDSS data archive. b) Developping an appropriate algorithm called Unresolved Galaxy Classifier (UGC). The algorithm is being developed implementing the Support Vector Machines (SVM), a supervised training technique. This algorithm utilizes Gaia simulated BP/RP galaxy spectra of our synthetic galaxy library.