Strong Correlation between Galactic HI-to-stellar Mass Ratio And Halo Spin Explored by HI-rich Galaxies

TL;DR

This study finds a strong correlation between the halo spin and the ratio of HI gas to stellar mass in galaxies, indicating a universal formation process affecting gas retention and star formation.

Contribution

The paper introduces a semi-analytic method to estimate halo spins for a large galaxy sample and demonstrates their correlation with HI-to-stellar mass ratios.

Findings

Halo spin correlates strongly with HI-to-stellar mass ratio.

Higher halo spin reduces angular momentum loss and gas condensation.

Results support a universal galaxy formation scenario.

Abstract

Using a semi-analytic approach, we estimate halo spins for a large sample of HI-rich galaxies from the Arecibo Legacy Fast Alfa Survey and examine the correlation between HI mass fractions and halo spins. Our analysis reveals a strong correlation between halo spin and the HI-to-stellar mass ratio in both low-mass and massive galaxy samples. This finding suggests a universal formation scenario: higher halo spin reduces angular momentum loss and gas condensation, leading to lower star formation rates and weaker feedback, which in turn helps retain gas within dark matter halos.