This paper introduces the HiddenValley simulations, a set of trillion-particle N-body simulations in gigaparsec volumes aimed at intensity mapping science. We present 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.
Intensity mapping with neutral hydrogen and the Hidden Valley simulations / C. Modi, E. Castorina, Y. Feng, M. White. - In: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. - ISSN 1475-7516. - 2019:9(2019 Sep).
|Titolo:||Intensity mapping with neutral hydrogen and the Hidden Valley simulations|
CASTORINA, EMANUELE (Primo)
|Parole Chiave:||baryon acoustic oscillations; cosmological simulations; galaxy clustering; redshift surveys|
|Settore Scientifico Disciplinare:||Settore FIS/05 - Astronomia e Astrofisica|
|Data di pubblicazione:||set-2019|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1088/1475-7516/2019/09/024|
|Appare nelle tipologie:||01 - Articolo su periodico|