Theoretical and observational constraints on the H i intensity power spectrum
Padmanabhan, Hamsa ; Choudhury, T. Roy ; Refregier, Alexandre
In: Monthly Notices of the Royal Astronomical Society, 2015, vol. 447, no. 4, p. 3745-3755
Aggiungi alla tua lista- Summary
- Mapping of the neutral hydrogen (H i) 21-cm intensity fluctuations across redshifts promises a novel and powerful probe of cosmology. The neutral hydrogen gas mass density $\Omega _{\rm H\,\small {i}}$ and bias parameter $b_{\rm H\,\small {i}}$ are key astrophysical inputs to the H i intensity fluctuation power spectrum. We compile the latest theoretical and observational constraints on $\Omega _{\rm H\,\small {i}}$ and $b_{\rm H\,\small {i}}$ at various redshifts in the post-reionization universe. Constraints are incorporated from galaxy surveys, H i intensity mapping experiments, damped Lyman α system observations, theoretical prescriptions for assigning H i to dark matter haloes and the results of numerical simulations. Using a minimum variance interpolation scheme, we obtain the predicted uncertainties on the H i intensity fluctuation power spectrum across redshifts 0-3.5 for three different confidence scenarios. We provide a convenient tabular form for the interpolated values of $\Omega _{\rm H\,\small {i}}$, $b_{\rm H\,\small {i}}$ and the H i power spectrum amplitude and their uncertainties. We discuss the consequences for the measurement of the power spectrum by current and future intensity mapping experiments