{
  "id": "2002.10717",
  "version": "v1",
  "published": "2020-02-25T08:03:04.000Z",
  "updated": "2020-02-25T08:03:04.000Z",
  "title": "ASASSN-16oh: nova outburst with no-mass-ejection -- A new type of supersoft X-ray sources in old populations",
  "authors": [
    "Mariko Kato",
    "Hideyuki Saio",
    "Izumi Hachisu"
  ],
  "comment": "21 pages, 10 figures, to appear in ApJ",
  "categories": [
    "astro-ph.SR",
    "astro-ph.HE"
  ],
  "abstract": "ASASSN-16oh is a peculiar transient supersoft X-ray source without mass-ejection signature in the field of the Small Magellanic Cloud. Maccarone et al. (2019) concluded that ASASSN-16oh is the first dwarf nova with supersoft X-ray originated from an equatorial accretion belt on a white dwarf (WD). Hillman et al. (2019) proposed a thermonuclear runaway model that both the X-rays and $V$/$I$ photons are emitted from the hot WD. We calculated the same parameter models as Hillman et al.'s and found that they manipulated on/off the mass-accretion, and their best fit $V$ light curves are 6 mag fainter, and decay about 10 times slower, than that of ASASSN-16oh. We propose a nova model induced by high rate mass-accretion during a dwarf nova outburst, i.e., the X-rays originate from a surface of the hydrogen-burning WD whereas the $V/I$ photons from the irradiated disk. Our model explains the main observational properties of ASASSN-16oh. We also obtained thermonuclear runaway models with no-mass-ejection for a wide range of parameters of the WD mass and mass accretion rates including both natural and forced novae in low-metal environments of $Z=0.001$ and $Z=0.0001$. They are a new type of periodic supersoft X-ray sources with no-mass-ejection, and also a bright transient in $V$/$I$ bands if they have a large disk. We suggest that such objects are a candidate of type Ia supernova progenitors because its mass is increasing at a very high efficiency $(\\sim 100 \\%)$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-02-25T08:03:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "nova outburst",
      "old populations",
      "asassn-16oh",
      "thermonuclear runaway model",
      "no-mass-ejection"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}