{
  "id": "1409.1171",
  "version": "v1",
  "published": "2014-09-03T17:07:58.000Z",
  "updated": "2014-09-03T17:07:58.000Z",
  "title": "Combined CO & Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star Formation Rate and Stellar Mass",
  "authors": [
    "R. Genzel",
    "L. J. Tacconi",
    "D. Lutz",
    "A. Saintonge",
    "S. Berta",
    "B. Magnelli",
    "F. Combes",
    "S. García-Burillo",
    "R. Neri",
    "A. Bolatto",
    "T. Contini",
    "S. Lilly",
    "J. Boissier",
    "F. Boone",
    "N. Bouché",
    "F. Bournaud",
    "A. Burkert",
    "M. Carollo",
    "L. Colina",
    "M. C. Cooper",
    "P. Cox",
    "C. Feruglio",
    "N. M. Förster Schreiber",
    "J. Freundlich",
    "J. Gracia-Carpio",
    "S. Juneau",
    "K. Kovac",
    "M. Lippa",
    "T. Naab",
    "P. Salome",
    "A. Renzini",
    "A. Sternberg",
    "F. Walter",
    "B. Weiner",
    "A. Weiss",
    "S. Wuyts"
  ],
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We combine molecular gas masses inferred from CO emission in 500 star forming galaxies (SFGs) between z=0 and 3, from the IRAM-COLDGASS, PHIBSS1/2 and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion time scale (tdepl) and gas fraction (Mmolgas/M*) with redshift, specific star formation rate (sSFR) and stellar mass (M*) in SFGs. The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO-H2 mass conversion factor varies little within +-0.6 dex of the main sequence line, and less than a factor of 2 throughout this redshift range. We find that tdepl scales as (1+z)^-0.3 *(sSFR)^-0.5, with no M* dependence. The resulting steep redshift dependence of Mmolgas/M* ~ (1+z)^3 mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M* are driven by the flattening of the SFR-M* relation. At constant M*, a larger sSFR is due to a combination of an increasing gas fraction and a decreasing depletion time scale. As a result galaxy integrated samples of the Mmolgas-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine Mmolgas with an accuracy of +-0.1 dex in relative terms, and +-0.2 dex including systematic uncertainties.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-09-03T17:07:58.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "specific star formation rate",
      "molecular gas fractions",
      "dust scaling relations",
      "stellar mass",
      "mass conversion factor varies"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/800/1/20",
      "journal": "The Astrophysical Journal",
      "year": 2015,
      "month": "Feb",
      "volume": 800,
      "number": 1,
      "pages": 20
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2015ApJ...800...20G"
    }
  }
}