Gaia and the Extragalactic
Résumé
Gaia's main goal is to study the Milky Way and its stellar content and to provide us with their highly accurate astrometric and photometric parameters. However the satellite will also survey many other objects. Gaia will especially observe a few millions of tiny galaxies of the local Universe and will give us a unique chance to access to a whole sky survey of these objects that no ground-based survey such as Sloan Digital Sky Survey has ever recorded, thanks to its high resolution. We present here the "Extended Object" DPAC DU470 work to retrieve the morphology of such objects and a theoretical study concerning the expected detections by Gaia. We show that most of the detected galaxies by Gaia will be bulge-type and elliptical.