{
  "id": "0902.2392",
  "version": "v3",
  "published": "2009-02-13T21:00:22.000Z",
  "updated": "2009-06-19T13:20:15.000Z",
  "title": "Estimating the H I gas fractions of galaxies in the local Universe",
  "authors": [
    "Wei Zhang",
    "Cheng Li",
    "Guinevere Kauffmann",
    "Hu Zou",
    "Barbara Catinella",
    "Shiyin Shen",
    "Qi Guo",
    "Ruixiang Chang"
  ],
  "comment": "12 pages, 9 figures, accepted for publication in MNRAS",
  "journal": "MNRAS. 397 (2009) 1243-1253",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We use a sample of 800 galaxies with H I mass measurements from the HyperLeda catalogue and optical photometry from the fourth data release of the Sloan Digital Sky Survey to calibrate a new photometric estimator of the H I to-stellar mass ratio for nearby galaxies. Our estimator, which is motivated by the Kennicutt-Schmidt star formation law, is log(G_{HI}/S) = -1.73238(g-r) + 0.215182mu_i - 4.08451, where mu_i is the i-band surface brighteness and g-r is the optical colour estimated from the g- and r-band Petrosian apparent agnitudes. This estimator has a scatter of sigma = 0.31 dex in log(G_{HI}/S), compared to sigma ~ 0.4 dex for previous estimators that were based on colour alone. We investigate whether the residuals in our estimate of log(G_{HI}/S) depend in a systematic way on a variety of different galaxy properties. We find no effect as a function of stellar mass or 4000A break strength, but there is a systematic effect as a function of the concentration index of the light. We then apply our estimator to a sample of 10^5 emission-line galaxies in the SDSS DR4 and derive an estimate of the H I mass function, which is in excellent agreement with recent results from H I blind surveys. Finally, we re-examine the well-known relation between gas-phase metallicity and stellar mass and ask whether there is a dependence on H I-to-stellar mass ratio, as predicted by chemical evolution models. We do find that gas-poor galaxies are more metal rich at fixed stellar mass. We compare our results with the semi-analytic models of De Lucia & Blaizot, which include supernova feedback, as well as the cosmological infall of gas.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2009-06-19T13:20:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "local universe",
      "gas fractions",
      "sloan digital sky survey",
      "kennicutt-schmidt star formation law",
      "r-band petrosian apparent agnitudes"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1111/j.1365-2966.2009.15050.x",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2009,
      "month": "Aug",
      "volume": 397,
      "number": 3,
      "pages": 1243
    },
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 813295,
      "adsabs": "2009MNRAS.397.1243Z"
    }
  }
}