{
  "id": "1106.0757",
  "version": "v2",
  "published": "2011-06-03T20:14:52.000Z",
  "updated": "2012-10-22T19:59:29.000Z",
  "title": "The current star formation rate of K+A galaxies",
  "authors": [
    "Danielle Nielsen",
    "Roberto De Propris",
    "Susan E. Ridgway",
    "Tomotsugu Goto"
  ],
  "comment": "Accepted for publication in the Astrophysical Journal Letters",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We derive the stacked 1.4 GHz flux from FIRST (Faint Images of the Radio Sky at Twenty Centimeters) survey for 811 K+A galaxies selected from the SDSS DR7. For these objects we find a mean flux density of $56\\pm 9$ $\\mu$Jy. A similar stack of radio-quiet white dwarfs yields an upper limit of 43 $\\mu$Jy at a 5$\\sigma$ significance to the flux in blank regions of the sky. This implies an average star formation rate of 1.6 $\\pm$ 0.3 M$_{\\odot}$ year$^{-1}$ for K+A galaxies. However the majority of the signal comes from $\\sim$4% of K+A fields that have aperture fluxes above the $5\\sigma$ noise level of the FIRST survey. A stack of the remaining galaxies shows little residual flux consistent with an upper limit on star formation of 1.3 M$_{\\odot}$ year$^{-1}$. Even for a subset of 456 `young' (spectral ages $<$ 250 Myr) K+A galaxies we find that the stacked 1.4 GHz flux is consistent with no current star formation. Our data suggest that the original starburst has been terminated in the majority of K+A galaxies, but that this may represent part of a duty cycle where a fraction of these galaxies may be active at a given moment with dusty starbursts and AGNs being present.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2012-10-22T19:59:29.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "current star formation rate",
      "ghz flux",
      "average star formation rate",
      "radio-quiet white dwarfs yields",
      "little residual flux consistent"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/2041-8205/761/2/L16",
      "journal": "The Astrophysical Journal",
      "year": 2012,
      "month": "Dec",
      "volume": 761,
      "number": 2
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 912738,
      "adsabs": "2012ApJ...761L..16N"
    }
  }
}