SIMBAD references

We present an empirical method to measure the halo mass function (HMF) of galaxies. We determine the relation between the H I line width from single-dish observations and the dark matter halo mass (M₂₀₀) inferred from rotation-curve fits in the Spitzer Photometry and Accurate Rotation Curves (SPARC) database, then we apply this relation to galaxies from the H I Parkes All Sky Survey (HIPASS) to derive the HMF. This empirical HMF is well fit by a Schechter function, and matches that expected in the Λ Cold Dark Matter (ΛCDM) model over the range 10^10.5 < M₂₀₀ < 10¹² M_☉. More massive halos must be poor in neutral gas to maintain consistency with the power law predicted by ΛCDM. We detect no discrepancy at low masses. The lowest halo mass probed by HIPASS, however, is just greater than the mass scale where the Local Group missing satellite problem sets in. The integrated mass density associated with the dark matter halos of H I-detected galaxies sums to Ω_m,gal ≃ 0.03 over the probed mass range.