2020/10/31 by Zhaoting Chen, Laura Wolz, Marta Spinelli +2
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Intensity mapping #Omega #Pathfinder #Physics #Radio Astronomy Observations and Technology #Redshift #Spectral density #Statistics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stab386
published as Monthly Notices of the Royal Astronomical Society, Volume 502, Issue 4, April 2021, Pages 5259-5276 · 19 pages, 11 figures and 6 tables. Updated to match the published version in MNRAS. For the computational tool used in this paper see arXiv:2009.14066 and https://halomod.readthedocs.io/en/latest/examples/extension.html
openalex created_date 2020/10/22 · openalex publication_date 2021/02/10 · arxiv created 2021/03/20 · arxiv updated 2021/03/23 · openalex updated_date 2026/08/05
ABSTRACT We present a new halo model of neutral hydrogen (H i) calibrated to galaxy formation simulations at redshifts z ∼ 0.1 and z ∼ 1.0 that we employ to investigate the constraining power of interferometric H i intensity mapping on H i astrophysics. We demonstrate that constraints on the small-scale H i power spectrum can break the degeneracy between the H i density Ω _\rm H \small I and the H i bias b_\rm H \small I. For z ∼ 0.1, we forecast that an accurate measurement of Ω _\rm H \small I up to 6 per cent level precision and the large-scale H i bias b_\rm H \small I0 up to 1 per cent level precision can be achieved using Square Kilometre Array (SKA) pathfinder data from MeerKAT and Australian SKA Pathfinder (ASKAP). We also propose a new description of the H i shot noise in the halo model framework in which a scatter of the relation between the H i mass of galaxies and their host halo mass is taken into account. Furthermore, given the number density of H i galaxies above a certain H i mass threshold, future surveys will also be able to constrain the H i mass function using only the H i shot noise. This will lead to constraints at the 10 per cent level using the standard Schechter function. This technique will potentially provide a new way of measuring the H i mass function, independent from existing methods. We predict that the SKA will be able to further improve the low-redshift constraints by a factor of 3, as well as pioneering measurements of H i astrophysics at higher redshifts.