2016/07/31 by Hamsa Padmanabhan, Alexandre Réfrégier, Alexandre Refregier · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Markov chain Monte Carlo #Monte Carlo method #Physics #Redshift #Reionization #Scientific Research and Discoveries #Statistics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stw2706
published as MNRAS, Volume 464, Issue 4, p.4008-4017 (2017) · 10 pages, 9 figures, 2 tables; version accepted for publication in MNRAS
arxiv created 2016/10/18 · openalex publication_date 2016/10/19 · arxiv updated 2017/08/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We describe a combined halo model to constrain the distribution of neutral hydrogen (H i) in the post-reionization universe. We combine constraints from the various probes of H i at different redshifts: the low-redshift 21-cm emission line surveys, intensity mapping experiments at intermediate redshifts, and the Damped Lyman-Alpha (DLA) observations at higher redshifts. We use a Markov Chain Monte Carlo approach to combine the observations and place constraints on the free parameters in the model. Our best-fitting model involves a relation between neutral hydrogen mass |M_\rm H \small I| and halo mass M with a non-unit slope, and an upper and a lower cutoff. We find that the model fits all the observables but leads to an underprediction of the bias parameter of DLAs at z ∼ 2.3. We also find indications of a possible tension between the H i column density distribution and the mass function of H i-selected galaxies at z ∼ 0. We provide the central values of the parameters of the best-fitting model so derived. We also provide a fitting form for the derived evolution of the concentration parameter of H i in dark matter haloes, and discuss the implications for the redshift evolution of the H i–halo mass relation.