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| Paper: |
Estimating the H I Mass in SDSS Galaxies |
| Volume: |
408, The Starburst−AGN Connection |
| Page: |
80 |
| Authors: |
Zhang, W. |
| Abstract: |
We propose that the H I-to-stellar mass ratio of galaxies in the low-redshift Universe, GHI/S, can be estimated by a linear combination of their i-band surface brightness μt and g − r colour, with a scatter of μ = 0.31 dex. This estimator is obtained and calibrated with the help of a sample of 800 galaxies at z < 0.1 that have both optical photometry from the Sloan Digital Sky Survey (SDSS) and H i observation from the HyperLeda catalogues. We apply this estimator to ~ 105 galaxies in SDSS data release 4 and compute the abundance of galaxies as a function of their H I mass. The result is well consistent with previous studies that were based on real H I data. We also use our data to examine the correlation of the H I mass of star-forming galaxies with their stellar mass and metallicity, and find that more gas poor galaxies have larger stellar masses and higher metallicities. We also find that, at fixed stellar mass, galaxies are richer in gas if they are poorer in metal abundance. This implies that the scatter in metallicity of the stellar mass-metallicity relation is partially (if not totally) due to recent inflow of external fresh gas which reduces the metallicity of the galaxy. |
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