TY - JOUR

T1 - Galaxy formation in the Planck Millennium

T2 - the atomic hydrogen content of dark matter halos

AU - Baugh, C. M.

AU - Gonzalez-Perez, Violeta

AU - Lagos, Claudia D. P.

AU - Lacey, Cedric G.

AU - Helly, John

AU - Jenkins, Adrian

AU - Frenk, Carlos S.

AU - Benson, Andrew

AU - Bower, Richard

AU - Cole, Shaun

N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version C M Baugh, Violeta Gonzalez-Perez, Claudia D P Lagos, Cedric G Lacey, John C Helly, Adrian Jenkins, Carlos S Frenk, Andrew J Benson, Richard G Bower, Shaun Cole, Galaxy formation in the Planck Millennium: the atomic hydrogen content of dark matter haloes, Monthly Notices of the Royal Astronomical Society, Volume 483, Issue 4, March 2019, Pages 4922–4937 is available online at: https://academic.oup.com/mnras/article/483/4/4922/5251995

PY - 2019/3/1

Y1 - 2019/3/1

N2 - 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 $2.12 \times 10^{9} h^{-1} {\rm M_{\odot}}$ 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, $\approx 3 \times 10^{11} h^{-1} M_{\rm \odot}$. 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.

AB - 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 $2.12 \times 10^{9} h^{-1} {\rm M_{\odot}}$ 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, $\approx 3 \times 10^{11} h^{-1} M_{\rm \odot}$. 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.

KW - cosmology: theory

KW - galaxies: formation

KW - galaxies: haloes

U2 - 10.1093/mnras/sty3427

DO - 10.1093/mnras/sty3427

M3 - Journal article

VL - 483

SP - 4922

EP - 4937

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -