Lost and found dark matter in elliptical galaxies
Abstract
The kinematical properties of elliptical galaxies formed during the mergers of equal mass, stars+gas+dark matter spiral galaxies are compared to the observed low velocity dispersions found for planetary nebulae on the outskirts of ellipticals, which have been interpreted as pointing to a lack of dark matter in ellipticals (which poses a problem for the standard model of galaxy formation). We find that the velocity dispersion profiles of the stars in the simulated ellipticals match well the observed ones. The low outer stellar velocity dispersions are mainly caused by the radial orbits of the outermost stars, which, for a given binding energy must have low angular momentum to reach their large radial distances, usually driven out along tidal tails.
Cite
@article{arxiv.astro-ph/0601344,
title = {Lost and found dark matter in elliptical galaxies},
author = {Felix Stoehr and Gary A. Mamon and Avishai Dekel and Thomas J. Cox},
journal= {arXiv preprint arXiv:astro-ph/0601344},
year = {2009}
}
Comments
Talk presented at 21st IAP meeting, Mass Profiles andShapes of Cosmological Structures. Ed. G. A. Mamon, F. Combes, C. Deffayet & B. Fort (Paris: EDP), 4 pages, 3 figures (4 plots)