2026/07/23 by Tanya Tripty, Nishikanta Khandai, Saili Dutta +1
Physics and Astronomy · #astro-ph.GA #astro-ph.CO
We estimate the Galaxy Stellar Mass Function (GSMF) of HI gas-rich galaxies using the 100% ALFALFA (α) catalog, ∼ 98% of which have optical counterparts in the Sloan Digital Sky Survey (SDSS) and a subset of them have counterparts in GALEX SDSS WISE Legacy Catalogue-2(GSWLC-2). We use the mass estimates from this subset which combines UV, optical and IR bands with individual dust corrections to recalibrate optical stellar mass estimates. We use a non-parametric method to estimate the GSMF of these gas-rich galaxies. The resulting, HI-selected GSMF is consistent with a single Schechter function with best-fit parameters \ϕ_* (10-3 h703 Mpc-3 dex-1), log10 (M_*/M\odot) + 2log10 h70, α\ = \2.30+0.12-0.12, 10.83+0.01-0.01, -1.14+0.02-0.02\ . Additionally, the red and blue populations are each well described by a single Schechter function. After correcting for selection effects, we find that the red population accounts for only ∼18% of gas-rich galaxies by number, yet contributes ∼54% of the total stellar mass, with the blue population accounting for the rest. Using an optically selected sample and a joint optical-HI sample, we find gas-rich galaxies represent ∼ 33% of the total stellar mass density and ∼ 39% of the total galaxy number counts in the local Universe. We use the GSMF and the HI mass function (HIMF) of the HI-selected sample to obtain the M\rm HI-M\rm star relation, which is free from selection bias.