# The HI content of dark matter halos at z ≈ 0 from ALFALFA

DOI:
10.1093/mnras/stz1118
Publication date:
01/04/2019
Main author:
Obuljen, Andrej
IAA authors:
Jones, Michael
Authors:
Obuljen, Andrej;Alonso, David;Villaescusa-Navarro, Francisco;Yoon, Ilsang;Jones, Michael
Journal:
Monthly Notices of the Royal Astronomical Society
Refereed:
Yes
Publication type:
Article
Pages:
5124-5138
Abstract:
We combine information from the clustering of HI galaxies in the 100% data release of the Arecibo Legacy Fast ALFA survey (ALFALFA), and from the HI content of optically-selected galaxy groups found in the Sloan Digital Sky Survey (SDSS) to constrain the relation between halo mass M<SUB>h</SUB> and its average total HI mass content M<SUB>HI</SUB>. We model the abundance and clustering of neutral hydrogen through a halo-model-based approach, parametrizing the M<SUB>HI</SUB>(M<SUB>h</SUB>) relation as a power law with an exponential mass cutoff. To break the degeneracy between the amplitude and low-mass cutoff of the M<SUB>HI</SUB>(M<SUB>h</SUB>) relation, we also include a recent measurement of the cosmic HI abundance from the α.100 sample. We find that all datasets are consistent with a power-law index α = 0.48 ± 0.08 and a cutoff 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 magneto-hydrodynamical simulations, and find both to be in good qualitative agreement, although the data favours a significantly larger cutoff mass that is consistent with the higher cosmic HI abundance found in simulations. Both data and simulations seem to predict a similar value for the HI bias (b_HI=0.878^{+0.022}_{-0.023}) and shot-noise power (P_SN=94^{+20}_{-18} [h^{-1}Mpc]^3) at redshift z = 0.
Database:
SCOPUS
URL:
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067950183&doi=10.1093%2fmnras%2fstz1118&partnerID=40&md5=6bdf7a534174329ea5de6e5ac2229b18