The HI Content of Local Late-Type Galaxies

TL;DR

This paper establishes a strong correlation between the neutral hydrogen (HI) mass and stellar mass in late-type galaxies, revealing insights into galaxy formation and baryonic component dependencies.

Contribution

It provides a new, robust relationship between HI and stellar mass in late-type galaxies, supported by multiple data sources and cross-validation methods.

Findings

HI mass correlates tightly with stellar mass over three orders of magnitude.

Derived the HI versus halo mass relationship.

Highlighted galaxy formation processes and baryonic inefficiencies.

Abstract

We present a solid relationship between the neutral hydrogen (HI) disk mass and the stellar disk mass of late-type galaxies in the local universe. This relationship is derived by comparing the stellar disk mass function from the Sloan Digital Sky Survey and the HI mass function from the HI Parkes All Sky Survey (HIPASS). We find that the HI mass in late-type galaxies tightly correlates with the stellar mass over three orders of magnitude in stellar disk mass. We cross-check our result with that obtained from a sample of HIPASS objects for which the stellar mass has been obtained by inner kinematics. In addition, we derive the HI versus halo mass relationship and the dependence of all the baryonic components in spirals on the host halo mass. These relationships bear the imprint of the processes ruling galaxy formation, and highlight the inefficiency of galaxies both in forming stars and in retaining their pristine HI gas.