The Draco dwarf in CDM and MOND
Abstract
We present interpretations of the line-of-sight velocity distribution of stars in the Draco dwarf spheroidal galaxy in terms of CDM and MOND assuming constant mass-to-light ratio and anisotropy. We estimate the two parameters by fitting the line-of-sight velocity dispersion and kurtosis profiles for stellar samples differing by a number of stars rejected as interlopers. The results of the fitting procedure for CDM, high mass-to-light ratio (131-141 solar units in V-band) and weakly tangential orbits, are similar for different samples, but the quality of the fit is much worse when fewer interlopers are removed. For MOND, the derived mass-to-light ratio (21 solar units) is too large to be explained by the stellar content of the galaxy.
Cite
@article{arxiv.astro-ph/0508668,
title = {The Draco dwarf in CDM and MOND},
author = {Ewa L. Lokas and Gary A. Mamon and Francisco Prada},
journal= {arXiv preprint arXiv:astro-ph/0508668},
year = {2009}
}
Comments
6 pages, 4 figures, invited contribution to the proceedings of the XXIst IAP Colloquium "Mass Profiles and Shapes of Cosmological Structures", Paris 4-9 July 2005, Editors: G. Mamon, F. Combes, C. Deffayet, B. Fort, EDP Sciences, in press