{
  "id": "1505.00777",
  "version": "v1",
  "published": "2015-05-04T20:00:22.000Z",
  "updated": "2015-05-04T20:00:22.000Z",
  "title": "Late-Time Photometry of Type Ia Supernova SN2012cg Reveals the Radioactive Decay of $^{57}$Co",
  "authors": [
    "Or Graur",
    "David Zurek",
    "Michael M. Shara",
    "Adam G. Riess"
  ],
  "comment": "Submitted, comments welcome. 14 pages, 2 figures, 1 table",
  "categories": [
    "astro-ph.HE",
    "astro-ph.CO"
  ],
  "abstract": "Seitenzahl et al. (2009) have predicted that $\\sim 3$ years after its explosion, the light we receive from a Type Ia supernova will come mostly from reprocessing of electrons and X-rays emitted by the radioactive decay chain $^{57}{\\rm Co}~\\to~^{57}{\\rm Fe}$, instead of positrons from the decay chain $^{56}{\\rm Co}~\\to~^{56}{\\rm Fe}$ that dominates the supernova light at earlier times. Using the Hubble Space Telescope, we followed the light curve of the Type Ia supernova SN2012cg out to $1055$ days after maximum light. Our measurements are consistent with the light curves predicted by the contribution of energy from the reprocessing of electrons and X-rays emitted by the decay of $^{57}$Co. This provides conclusive evidence that $^{57}$Co is produced in Type Ia supernova explosions. The ratio of luminosities produced by the decays of $^{57}$Co and $^{56}$Co, a strong constraint on any Type Ia supernova explosion model, is in the range $(0.4$ - $8.5)\\times10^{-3}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-05-04T20:00:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "type ia supernova sn2012cg",
      "radioactive decay",
      "late-time photometry",
      "type ia supernova explosion model",
      "decay chain"
    ],
    "publication": {
      "doi": "10.3847/0004-637X/819/1/31"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1366123
    }
  }
}