Virgo Cluster Early‐Type Dwarf Galaxies with the Sloan Digital Sky Survey. III. Subpopulations: Distributions, Shapes, Origins
Year: 2007
Type: article
Abstract: From a quantitative analysis of 413 Virgo Cluster early-type dwarf galaxies (dEs) with SDSS imaging data, we find that the dE class can be divided into multiple subpopulations that differ significantly in their morphology and clustering properties. Three dE subclasses are shaped like thick disks and show no central clustering: (1) dEs with disk features like spiral arms or bars, (2) dEs with central star formation, and (3) ordinary, bright dEs that have no or only a weak nucleus. These populations probably formed from infalling progenitor galaxies. In contrast, ordinary nucleated dEs follow the picture of classical dwarf elliptical galaxies in that they are spheroidal objects and are centrally clustered like E and S0 galaxies, indicating that they have resided in the cluster for a long time or were formed along with it. These results define a morphology-density relation within the dE class. We find that the difference in the clustering properties of nucleated dEs and dEs with no or only a weak nucleus is not caused by selection biases, as opposed to previously reported suggestions. The correlation between surface brightness and observed axial ratio favors oblate shapes for all subclasses, but our derivation of intrinsic axial ratios indicates the presence of at least some triaxiality. We discuss possible interrelations and formation mechanisms (ram pressure stripping, tidally induced star formation, harassment) of these dE subpopulations.
Source: The Astrophysical Journal
DOI: 10.1086/513090
Authors: Thorsten Lisker, Eva K. Grebel, Bruno Binggeli, Katharina Glatt
Institution: University of Basel
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Princeton University, Ohio State University, California Institute of Technology, University of Washington, Johns Hopkins University, University of Pittsburgh, Case Western Reserve University, Drexel University, Universität Basel, University of Portsmouth, New Mexico State University, University of Cambridge, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Chinese Academy of Sciences, Max-Planck-Gesellschaft, Max-Planck-Institut für Astronomie, Jet Propulsion Laboratory, U.S. Naval Observatory, Fermilab, Los Alamos National Laboratory
OpenAlex ID: W2001685500