2018/08/31 by C. M. Baugh, Violeta Gonzalez-Perez, Claudia D. P. Lagos +7 · 1 citation
Physics and Astronomy · #astro-ph.GA
paper · pdf · doi:10.1093/mnras/sty3427
published as Monthly Notices of the Royal Astronomical Society, 2019, 483, 4922-4937 · 17 pages, accepted by MNRAS
arxiv created 2019/06/11 · arxiv updated 2019/06/12
We present recalibrations of the GALFORM semi-analytical model of galaxy formation in a new N-body simulation with the Planck cosmology. The Planck Millennium simulation uses more than 128 billion particles to resolve the matter distribution in a cube of 800 Mpc on a side, which contains more than 77 million dark matter haloes with mass greater than 2.12 × 109 h-1 \rm M\odot at the present day. Only minor changes to a very small number of model parameters are required in the recalibration. We present predictions for the atomic hydrogen content (HI) of dark matter halos, which is a key input into the calculation of the HI intensity mapping signal expected from the large-scale structure of the Universe. We find that the HI mass - halo mass relation displays a clear break at the halo mass above which AGN heating suppresses gas cooling, ≈ 3 × 1011 h-1 M\rm \odot. Below this halo mass, the HI content of haloes is dominated by the central galaxy; above this mass it is the combined HI content of satellites that prevails. We find that the HI mass - halo mass relation changes little with redshift up to z=3. The bias of HI sources shows a scale dependence that gets more pronounced with increasing redshift.