{
  "id": "1604.07808",
  "version": "v1",
  "published": "2016-04-26T19:31:00.000Z",
  "updated": "2016-04-26T19:31:00.000Z",
  "title": "The Soft X-ray Spectrum of the High Mass X-Ray Binary V0332+53 in Quiescence",
  "authors": [
    "K. Elshamouty",
    "C. Heinke",
    "R. Chouinard"
  ],
  "comment": "6 pages, 3 figures, 1 table, submitted to MNRAS",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "The propeller effect should cut off accretion in fast-spinning neutron star high mass X-ray binaries (HMXBs) at low mass transfer rates. However, accretion continues in some HMXBs at $L_{x} < 10^{34}$ erg s$^{-1}$, as evidenced by continuing pulsations. Indications of spectral softening in systems in the propeller regime suggest that some HMXBs are undergoing fundamental changes in their accretion regime. A 39 ks \\textit{XMM-Newton} observation of the transient HMXB V0332+53 found it at a very low X-ray luminosity ($L_{x} \\sim 4\\times 10^{32}$ erg s${^{-1}}$). A power-law spectral fit requires an unusually soft spectral index ($4.4^{+0.9}_{-0.6}$), while a magnetized neutron star atmosphere model, with temperature \\lt\\ 6.7$\\pm 0.2$ K and inferred emitting radius of $\\sim0.2-0.3$ km, gives a good fit. We suggest that the quiescent X-ray emission from V0332+53 is mainly from a hot spot on the surface of the neutron star. We could not detect pulsations from V0332+53, due to the low count rate. Due to the high $N_H$, thermal emission from the rest of the neutron star could be only weakly constrained, to \\lt\\ $<$6.14$^{+0.05}_{-6.14}$ K, or $<3\\times10^{33}$ erg s${^{-1}}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-04-26T19:31:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high mass x-ray binary",
      "soft x-ray spectrum",
      "neutron star atmosphere model",
      "neutron star high mass",
      "star high mass x-ray"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2016arXiv160407808E",
      "inspire": 1452541
    }
  }
}