{
  "id": "1706.06109",
  "version": "v1",
  "published": "2017-06-19T18:00:06.000Z",
  "updated": "2017-06-19T18:00:06.000Z",
  "title": "Very massive stars, pair-instability supernovae and intermediate-mass black holes with the SEVN code",
  "authors": [
    "Mario Spera",
    "Michela Mapelli"
  ],
  "comment": "12 pages, 9 figures, 3 tables, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.SR",
    "astro-ph.HE"
  ],
  "abstract": "Understanding the link between massive ($\\gtrsim 30$ M$_{\\odot{}}$) stellar black holes (BHs) and their progenitor stars is a crucial step to interpret observations of gravitational-wave events. In this paper, we discuss the final fate of very massive stars (VMSs), with zero-age main sequence (ZAMS) mass $>150$ M$_{\\odot}$, accounting for pulsational pair-instability supernovae (PPISNe) and for pair-instability supernovae (PISNe). We describe an updated version of our population synthesis code SEVN, in which we added stellar evolution tracks for VMSs with ZAMS mass up to $350 $M$_{\\odot{}}$ and we included analytical prescriptions for PPISNe and PISNe. We use the new version of SEVN to study the BH mass spectrum at different metallicity $Z$, ranging from $Z=2.0\\times 10^{-4}$ to $Z=2.0\\times 10^{-2}$. The main effect of PPISNe and PISNe is to favour the formation of BHs in the mass range of the first gravitational-wave event (GW150914), while they prevent the formation of remnants with mass 60 - 120 M$_{\\odot{}}$. In particular, we find that PPISNe significantly enhance mass loss of metal-poor ($Z\\leq 2.0\\times 10^{-3}$) stars with ZAMS mass $60\\leq $M$_{\\mathrm{ZAMS}}/$M$_{\\odot{}}\\leq 125$. In contrast, PISNe become effective only for moderately metal-poor ($Z<8.0\\times 10^{-3}$) VMSs. VMSs with M$_{\\rm ZAMS}\\gtrsim{}220$ M$_\\odot$ and $Z<10^{-3}$ do not undergo PISNe and form intermediate-mass BHs (IMBHs, with mass $\\gtrsim 200 $M$_{\\odot{}}$) via direct collapse.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-06-19T18:00:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "intermediate-mass black holes",
      "pair-instability supernovae",
      "massive stars",
      "sevn code",
      "zams mass"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}