{
  "id": "0902.3248",
  "version": "v2",
  "published": "2009-02-19T14:01:51.000Z",
  "updated": "2009-07-06T18:17:17.000Z",
  "title": "NTT, Spitzer and Chandra spectroscopy of SDSSJ095209.56+214313.3: the most luminous coronal-line supernova ever observed, or a stellar tidal disruption event ?",
  "authors": [
    "S. Komossa",
    "H. Zhou",
    "A. Rau",
    "M. Dopita",
    "A. Gal-Yam",
    "J. Greiner",
    "J. Zuther",
    "M. Salvato",
    "D. Xu",
    "H. Lu",
    "R. Saxton",
    "M. Ajello"
  ],
  "comment": "18 pages, 8 (colour) figures; to appear in August 2009 issue of ApJ",
  "journal": "Astrophys.J.701:105-121,2009",
  "doi": "10.1088/0004-637X/701/1/105",
  "categories": [
    "astro-ph.GA",
    "astro-ph.HE"
  ],
  "abstract": "The galaxy SDSSJ0952+2143 showed remarkable emission-line properties first reported in 2008 (paper I), which are the consequence of a powerful high-energy flare. Here we report follow-up observations of SDSSJ0952+2143, and discuss outburst scenarios in terms of stellar tidal disruption by a SMBH, peculiar variability of an AGN, and a supernova explosion. The optical spectrum of SDSSJ0952+2143 exhibits several peculiarities: an exceptional ratio of [FeVII] transitions over [OIII], a dramatic decrease by a factor of 10 of the highest-ionization lines, a very unusual and variable Balmer line profile including a triple-peaked narrow component with two unresolved horns, and a large Balmer decrement. The MIR emission measured with the Spitzer IRS in the narrow 10-20mu band is extraordinarily luminous (3.5 x 10^{43} erg\\s). The IRS spectrum shows a bump around ~11mu and an increase towards longer wavelengths, reminiscent of silicate emission. The strong MIR excess over the NIR implies the dominance of relatively cold dust. The X-ray luminosity of 10^{41} erg\\s measured with Chandra is below that typically observed in AGN. Similarities of SDSSJ0952+2143 with some extreme supernovae suggest the explosion of a supernova of Type IIn. However, an extreme accretion event in a low-luminosity AGN or inactive galaxy, especially stellar tidal disruption, remain possibilities, which could potentially produce a very similar emission-line response. If indeed a supernova, SDSSJ0952+2143 is one of the most distant X-ray and MIR detected SNe known so far, the most MIR luminous, and one of the most X-ray luminous. It is also by far the most luminous (>10^{40} erg\\s) in high-ionization coronal lines, exceeding previous SNe by at least a factor of 100 [abridged].",
  "revisions": [
    {
      "version": "v2",
      "updated": "2009-07-06T18:17:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "stellar tidal disruption event",
      "luminous coronal-line supernova",
      "chandra spectroscopy",
      "similar emission-line response",
      "report follow-up observations"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "The Astrophysical Journal",
      "year": 2009,
      "month": "Aug",
      "volume": 701,
      "number": 1,
      "pages": 105
    },
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 813680,
      "adsabs": "2009ApJ...701..105K"
    }
  }
}