Semi-Empirical Catalog of Early-Type Galaxy-Halo Systems: Dark Matter Density Profiles, Halo Contraction and Dark Matter Annihilation strength
2012
33 pages
Published in:
- JCAP 11 (2012) 004
e-Print:
- 1202.2716 [astro-ph.CO]
Report number:
- FERMILAB-PUB-12-890-T
Citations per year
Abstract: (arXiv)
With SDSS galaxy data and halo data from up-to-date N-body simulations we construct a semi-empirical catalog (SEC) of early-type systems by making a self-consistent bivariate statistical match of stellar mass (M_star) and velocity dispersion (sigma) with halo virial mass (M_vir). We then assign stellar mass profile and velocity dispersion profile parameters to each system in the SEC using their observed correlations with M_star and sigma. Simultaneously, we solve for dark matter density profile of each halo using the spherical Jeans equation. The resulting dark matter density profiles deviate in general from the dissipationless profile of NFW or Einasto and their mean inner density slope and concentration vary systematically with M_vir. Statistical tests of the distribution of profiles at fixed M_vir rule out the null hypothesis that it follows the distribution predicted by N-body simulations for M_vir ~< 10^{13.5-14.5} M_solar. These dark matter profiles imply that dark matter density is, on average, enhanced significantly in the inner region of halos with M_vir ~< 10^{13.5-14.5} M_solar supporting halo contraction. The main characteristics of halo contraction are: (1) the mean dark matter density within the effective radius has increased by a factor varying systematically up to ~ 3-4 at M_vir = 10^{12} M_solar, and (2) the inner density slope has a mean of Note:
- 43 pages, 20 figures, JCAP, revised and accepted version
- galaxy dynamics
- galaxy formation
- dark matter experiments
- dark matter: density
- dark matter: annihilation
- velocity: dispersion
- dark matter: galaxy: halo
- dissipation
- embedding
- sloan digital sky survey
References(73)
Figures(20)