Title: Intensity mapping with neutral hydrogen and the Hidden Valley simulations

Abstract

Our work presents the Hidden Valley simulations, a set of trillion-particle N-body simulations in gigaparsec volumes aimed at intensity mapping science. We offer details of the simulations and their convergence, then specialize to the study of 21-cm fluctuations between redshifts 2 and 6. Neutral hydrogen is assigned to halos using three prescriptions, and we investigate the clustering in real and redshift-space at the 2-point level. In common with earlier work we find the bias of HI increases from near 2 at z = 2 to 4 at z = 6, becoming more scale dependent at high z. The level of scale-dependence and decorrelation with the matter field are as predicted by perturbation theory. Due to the low mass of the hosting halos, the impact of fingers of god is small on the range relevant for proposed 21-cm instruments. We show that baryon acoustic oscillations and redshift-space distortions could be well measured by such instruments. Taking advantage of the large simulation volume, we assess the impact of fluctuations in the ultraviolet background, which change HI clustering primarily at large scales.

Authors:

Modi, Chirag ^[1]; Castorina, Emanuele ^[1]; Feng, Yu ^[1]; White, Martin ^[1]

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+ Show Author Affiliations

1. Univ. of California, Berkeley, CA (United States)

Publication Date:

2019-09-12

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1572844

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Cosmology and Astroparticle Physics

Additional Journal Information:

Journal Volume: 2019; Journal Issue: 09; Journal ID: ISSN 1475-7516

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; cosmological parameters from LSS; power spectrum; 21 cm; galaxy clustering