Letter to the Editor
Discovery of a new M 32-like “Compact Elliptical” galaxy in the halo of the Abell 496 cD galaxy *
Observatoire de Paris-Meudon, LERMA, UMR 8112, 61 Av. de l'Observatoire, 75014 Paris, France e-mail: firstname.lastname@example.org
2 Sternberg Astronomical Institute, Moscow State University, 13 Universitetski prospect, 119992 Moscow, Russia
3 Observatoire de Paris-Meudon, LUTH, UMR 8102, 5 place Jules Janssen, 92195 Meudon, France
4 Observatoire de Paris-Meudon, GEPI, UMR 8111, 5 place Jules Janssen, 92195 Meudon, France
5 Institut d'Astrophysique de Paris, CNRS, UMR 7095, Université Pierre et Marie Curie, 98bis Bd Arago, 75014 Paris, France
6 Instituto de Astronomia, Geofísica e C. Atmosf./USP, R. do Matão 1226, 05508-090 São Paulo/SP, Brazil
7 Laboratoire d'Astrophysique de Marseille, UMR 6110, Traverse du Siphon, 13012 Marseille, France
8 Observatoire de la Côte d'Azur, Laboratoire Cassiopée, UMR 6202, BP 4229, 06304 Nice Cedex 4, France
Accepted: 13 March 2007
Aims.“Compact ellipticals” are so rare that a search for M 32 analogs is needed to ensure the very existence of this class.
Methods.We report here the discovery of A496cE, a M 32 twin in the cluster Abell 496, located in the halo of the central cD.
Results.Based on CFHT and HST imaging we show that the light profile of A496cE requires a two component fit: a Sérsic bulge and an exponential disc. The spectrum of A496cE obtained with the ESO-VLT FLAMES/Giraffe spectrograph can be fit by a stellar synthesis spectrum dominated by old stars, with high values of [Mg/Fe] and velocity dispersion.
Conclusions.The capture of A496cE by the cD galaxy and tidal stripping of most of its disc are briefly discussed.
Key words: galaxies: evolution / galaxies: dwarf / galaxies: bulges / galaxies: kinematics and dynamics / galaxies: elliptical and lenticular, cD
Based on observations obtained at the Canada-France-Hawaii Telescope (program 03BF12) which is operated by the National Research Council of Canada, the Institut des Sciences de l'Univers of the Centre National de la Recherche Scientifique and the University of Hawaii. Also based on ESO VLT data (program 074.A-0533), and on HST archive data (proposals 5121 and 8683).
© ESO, 2007