DINGO/GAMA /WAVES: HI-halo mass relation

TL;DR

This study explores the relationship between neutral atomic hydrogen and dark matter halo mass across a wide range, revealing a double power-law form and emphasizing the role of satellites in massive halos.

Contribution

It introduces a novel stacking method incorporating photometric members to extend HI analysis beyond spectroscopic limits, improving halo HI content estimates.

Findings

The HI-halo mass relation follows a double power-law with a turnover at ~10^{11.2} M_sun.

Satellites dominate the HI budget in halos above 6 x 10^{12} M_sun.

Including photometric members increases HI measurements in massive halos by 1.5-3 times.

Abstract

We investigate the relation between neutral atomic hydrogen (HI) and dark matter halo mass (HIHM) using observations from the Deep Investigation of Neutral Gas Origins (DINGO) pilot survey 100h data, combined with spectroscopic data from the Galaxy and Mass Assembly (GAMA) survey and photometric data from the Wide Area VISTA Extragalactic Survey (WAVES) photometric catalog. We employ a combination of direct detections and spectral stacking to probe the HI content of halos across a wide mass range ($10^{10.5} \lesssim M_\mathrm{h}/M_\odot \lesssim 10^{14.5}$). By incorporating WAVES photometric members on top of the existing GAMA group catalog, we present a novel approach of extending stacking analyses beyond spectroscopic completeness limits, enabling recovery of satellite HI content otherwise missed. We find that the HIHM relation exhibits a double power-law form, with a turnover near $M_\mathrm{h} \sim 10^{11.2} \text{ M}_\odot$. Central galaxies dominate the halo HI budget below $M_\mathrm{h} \sim 6 \times 10^{12} \text{ M}_\odot$, while satellites dominate at higher halo masses. Including photometric members increases the measured HI content in halos above $10^{13} \text{ M}_\odot$ by a factor of 1.5-3, highlighting the importance of gas-rich satellites in the group and cluster regime. Comparison with previous group-stacking studies shows that low-surface brightness galaxies, and intra-group HI structures contribute only a minor fraction to the total HI mass in group and cluster halos, as the summed galaxy HI masses are consistent with the total halo HI content.