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Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
A population of compact elliptical galaxies detected with the Virtual Observatory
Igor Chilingarian1, Véronique Cayatte, Yves Revaz
1Observatoire de Paris-Meudon, Laboratoire d'Etude du Rayonnement et de la Matiére en Astrophysique, UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, France. igor.chilingarian@obspm.fr
Abstract:
Compact elliptical galaxies are characterized by small sizes and high stellar densities. They are thought to form through tidal stripping of massive progenitors. However, only a handful of them were known, preventing us from understanding the role played by this mechanism in galaxy evolution. We present a population of 21 compact elliptical galaxies gathered with the Virtual Observatory. Follow-up spectroscopy and data mining, using high-resolution images and large databases, show that all the galaxies exhibit old metal-rich stellar populations different from those of dwarf elliptical galaxies of similar masses but similar to those of more massive early-type galaxies, supporting the tidal stripping scenario. Their internal properties are reproduced by numerical simulations, which result in compact, dynamically hot remnants resembling the galaxies in our sample.
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