Constraining a halo model for cosmological neutral hydrogen


Date

2017-02

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

Abstract

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 MHI 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.

Publication status

published

Editor

Book title

Volume

464 (4)

Pages / Article No.

4008 - 4017

Publisher

Oxford University Press

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Galaxies: evolution; Cosmology: observations; Radio lines: galaxies

Organisational unit

03928 - Refregier, Alexandre / Refregier, Alexandre check_circle

Notes

It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.

Funding

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