{
  "id": "1605.07781",
  "version": "v1",
  "published": "2016-05-25T09:00:47.000Z",
  "updated": "2016-05-25T09:00:47.000Z",
  "title": "The Oxygen Features in Type Ia Supernovae and the Implications for the Nature of Thermonuclear Explosions",
  "authors": [
    "Xulin Zhao",
    "Keiichi Maeda",
    "Xiaofeng Wang",
    "Lifan Wang",
    "Hanna Sai",
    "Jujia Zhang",
    "Tianmeng Zhang",
    "Fang Huang",
    "Liming Rui"
  ],
  "comment": "37 pages, 10 figures, accepted for publication in the Astrophysical Journal",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "The absorption feature O I 7773 is an important spectral indicator for type Ia supernovae (SNe~Ia) that can be used to trace the unburned material at outer layers of the exploding white dwarf. In this work, we use a large sample of SNe~Ia to examine this absorption at early phases (i.e., -13 days <t <-7 days), and make comparisons with the absorption features of Si~II 6355 and Ca~II near-infrared (NIR) triplet. We show that for a subgroup of spectroscopically normal SNe with normal photospheric velocities (i.e., v_si < 12,500 km s^{-1} at optical maximum), the line strength of high velocity feature (HVF) of O~I is inversely correlated with that of Si~II (or Ca~II), and this feature also shows a negative correlation with the luminosity of SNe Ia. This finding, together with other features we find for the O~I HVF, reveal that for this subgroup of SNe~Ia explosive oxygen burning occurs at the outermost layer of supernova and difference in burning there could lead to the observed diversity, which are in remarkable agreement with the popular delayed-detonation model of Chandrasekhar mass WD.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-05-25T09:00:47.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "type ia supernovae",
      "oxygen features",
      "thermonuclear explosions",
      "absorption feature",
      "implications"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 37,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1465626
    }
  }
}