{
  "id": "1409.6683",
  "version": "v1",
  "published": "2014-09-23T17:58:33.000Z",
  "updated": "2014-09-23T17:58:33.000Z",
  "title": "Early-type galaxies at intermediate redshift observed with HST WFC3: perspectives on recent star-formation",
  "authors": [
    "M. Rutkowski",
    "H. Jeong",
    "S. H. Cohen",
    "S. Kaviraj",
    "R. E. Ryan, Jr.",
    "R. A. Windhorst",
    "A. Koekemoer",
    "N. P. Hathi",
    "M. A. Dopita",
    "S. K. Yi"
  ],
  "comment": "Accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present an analysis of the stellar populations of 102 visually-selected early-type galaxies (ETGs) with spectroscopic redshifts (0.3<z<1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on {\\it Hubble Space Telescope} (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find a large fraction (~40%) are likely to have experienced a minor (f$\\lesssim$10% of stellar mass) burst of recent (t$\\lesssim$1 Gyr) star-formation. The measured ages and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (log(M[$M_{\\odot}$])>10.5) recently star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of RSF. We conclude that both mechanisms of the quenching of star-formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically-confirmed redshifts is relatively small, therefore a conclusion on the relative roles of both of these mechanisms remains an open question.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-09-23T17:58:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star-formation",
      "perspectives",
      "intermediate redshift etgs",
      "merger activity contribute",
      "hst wfc3 panchromatic"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/796/2/101",
      "journal": "The Astrophysical Journal",
      "year": 2014,
      "month": "Dec",
      "volume": 796,
      "number": 2,
      "pages": 101
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014ApJ...796..101R"
    }
  }
}