The bias of DLAs at z ~ 2.3: Evidence for very strong stellar feedback in shallow potential wells [CEA]

http://arxiv.org/abs/1403.1873


We discuss the recent BOSS measurement of a rather high bias factor for the host galaxies/haloes of Damped Lyman-alpha Absorbers (DLAs), in the context of our previous modelling of the physical properties of DLAs within the {\Lambda}CDM paradigm. Joint modelling of the column density distribution, the velocity width distribution of associated low ionization metal absorption, and the bias parameter suggests that DLAs are hosted by galaxies with dark matter halo masses in the range 10.5 < log Mv < 13, with a rather sharp cutoff at the lower mass end, corresponding to viral velocities of ~90 km/s. The observed properties of DLAs appear to suggest very efficient (stellar) feedback in haloes with masses/virial velocities below the cutoff and a large retained baryon fraction (> 35%) in haloes above the cutoff.

Read this paper on arXiv…

L. Barnes and M. Haehnelt
Tue, 11 Mar 14
31/66