Dark Matter in Elliptical Galaxies
Abstract
We review X-ray constraints on dark matter in giant elliptical galaxies (10^{12} M_sun <~ M_vir <~ 10^{13} M_sun) obtained using the current generation of X-ray satellites, beginning with an overview of the physics of the hot interstellar medium and mass modeling methodology. Dark matter is now firmly established in many galaxies, with inferred NFW concentration parameters somewhat larger than the mean theoretical relation. X-ray observations confirm that the total mass profile (baryons+DM) is close to isothermal (M ~ r), and new evidence suggests a more general power-law relation for the slope of the total mass profile that varies with the stellar half-light radius. We also discuss constraints on the baryon fraction, super-massive black holes, and axial ratio of the dark matter halo. Finally, we review constraints on non-thermal gas motions and discuss the accuracy of the hydrostatic equilibrium approximation in elliptical galaxies.
Cite
@article{arxiv.1104.0012,
title = {Dark Matter in Elliptical Galaxies},
author = {David A. Buote and Philip J. Humphrey},
journal= {arXiv preprint arXiv:1104.0012},
year = {2015}
}
Comments
36 pages, 11 figures. Abbreviated version of the article to appear in Hot Interstellar Matter in Elliptical Galaxies, eds. D.-W. Kim and S. Pellegrini, Astrophysics and Space Science Library (ASSL), Springer