Formation and evolution of dwarf early-type galaxies in the Virgo cluster I. Internal kinematics

© ESO, 2011. We thank the MAGPOP EU Marie Curie Training Network for financial support for the collaborating research visits and observations that led to this paper. E.T. acknowledges the financial support by the Spanish research project AYA2007-67752-C03-03. We thank Consolider-GTC project for partial financial support. This paper made use of the following public databases: SDSS, NED, HyperLEDA, GOLDMine. We are grateful to the anonymous referee for a critical report that has improved the quality of the paper.
We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster, obtained with the WHT and INT telescopes at the Roque de los Muchachos Observatory (La Palma, Spain). These data are used to study the origin of the dwarf elliptical galaxy population inhabiting clusters. We confirm that dEs are not dark matter dominated galaxies, at least not up to the half-light radius. We also find that the observed galaxies in the outer parts of the cluster are mostly rotationally supported systems with disky morphological shapes. Rotationally supported dEs have rotation curves similar to those of star-forming galaxies of similar luminosity and follow the Tully-Fisher relation. This is expected if dE galaxies are the descendants of low-luminosity star-forming systems that have recently entered the cluster environment and lost their gas due to a ram-pressure stripping event, quenching their star formation activity and transforming into quiescent systems, but conserving their angular momentum.
Ministerio de Ciencia e Innovación (MICINN)
Marie Curie Actions (UE)
Depto. de Física de la Tierra y Astrofísica
Fac. de Ciencias Físicas
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