The H I content of dark matter haloes at z ≈ 0 from ALFALFA

July 2019 • 2019MNRAS.486.5124O

Authors • Obuljen, Andrej • Alonso, David • Villaescusa-Navarro, Francisco • Yoon, Ilsang • Jones, Michael

Abstract • We combine information from the clustering of H I galaxies in the 100 per cent data release of the Arecibo Legacy Fast ALFA survey, and from the H I content of optically selected galaxy groups found in the Sloan Digital Sky Survey to constrain the relation between halo mass M_h and its average total H I mass content M_{H I}. We model the abundance and clustering of neutral hydrogen through a halo-model-based approach, parametrizing the M_{H I}(M_h) relation as a power law with an exponential mass cut-off. To break the degeneracy between the amplitude and low-mass cut-off of the M_{H I}(M_h) relation, we also include a recent measurement of the cosmic H I abundance from the α.100 sample. We find that all data sets are consistent with a power-law index α = 0.48 ± 0.08 and a cut-off halo mass log _{10}M_min/(h^{-1} M_☉)=11.18^{+0.28}_{-0.35}. We compare these results with predictions from state-of-the-art magnetohydrodynamical simulations, and find both to be in good qualitative agreement, although the data favours a significantly larger cut-off mass that is consistent with the higher cosmic H I abundance found in simulations. Both data and simulations seem to predict a similar value for the H I bias (b_{H I}=0.878^{+0.022}_{-0.023}) and shot-noise power (P_SN=94^{+20}_{-18} [h^{-1} Mpc]^3) at redshift z = 0.

Links

• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2019MNRAS.486.5124O
• PDF http://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/stz1118
• PDF https://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/stz1118
• PREPRINT http://arxiv.org/abs/1805.00934
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstz1118