We quantitatively investigate the dependence of central galaxy HI mass (MHI) on the stellar mass (M∗), halo mass (Mh), star formation rate (SFR), and central stellar surface density within 1 kpc (Σ1), taking advantage of the HI spectra stacking technique using both the Arecibo Fast Legacy ALFA Survey and the Sloan Digital Sky Survey. We find that the shapes of MHI–Mh and MHI–M∗ relations are remarkably similar for both star-forming and quenched galaxies, with massive quenched galaxies having constantly lower HI masses of around 0.6 dex. This similarity strongly suggests that neither halo mass nor stellar mass is the direct cause of quenching, but rather the depletion of HI reservoir. We find that the star formation and quenching of central galaxies are directly regulated by the available HI reservoir.
Prof. Hong Guo is a research professor at Shanghai Astronomical Observatory (SHAO). He got his PhD from SHAO in 2011 and worked as a postdoc fellow at Case Western Reserve University in 2011 and University of Utah at 2013, respectively. After that, he worked as a faculty member at SHAO in 2015. Prof. Guo’s primary research interests focus on using the galaxy clustering to understand the connection between galaxies and the dark matter halos.