{
  "id": "1705.09733",
  "version": "v1",
  "published": "2017-05-26T22:34:24.000Z",
  "updated": "2017-05-26T22:34:24.000Z",
  "title": "Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-ray Pulsars",
  "authors": [
    "JaeSub Hong",
    "Vallia Antoniou",
    "Andreas Zezas",
    "Frank Haberl",
    "Manami Sasaki",
    "Jeremy Drake",
    "Paul Plucinsky",
    "Silas Laycock"
  ],
  "comment": "24 pages, 19 figures, 11 tables, submitted to ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We have analyzed a total exposure of 1.4 Ms from 31 observations over a 1.2 deg$^2$ region in the SMC under a Chandra X-ray Visionary Program. Using the Lomb-Scargle and epoch folding techniques, we have detected periodic modulations from 20 pulsars and a new candidate pulsar. The survey also covers 11 other pulsars with no clear sign of periodic modulation. The 0.5-8 keV X-ray luminosity ($L_X$) of the pulsars ranges from $10^{34}$ to $10^{37}$ erg s$^{-1}$ at 60 kpc. All the Chandra sources with $L_X$ $\\gtrsim 4 \\times 10^{35}$ erg s$^{-1}$ exhibit X-ray pulsations. The X-ray spectra of the SMC pulsars (and high mass X-ray binaries) are in general harder than those of the SMC field population. All but SXP~8.02 can be fitted by an absorbed power-law model with a photon index of $\\Gamma$ $\\lesssim$ 1.5. The X-ray spectrum of the known magnetar SXP~8.02 is better fitted with a two-temperature blackbody model. Newly measured pulsation periods of SXP~51.0, SXP~214 and SXP~701 are significantly different from the previous XMM-Newton and RXTE measurements. This survey provides a rich data set for energy-dependent pulse profile modeling. Six pulsars show an almost eclipse-like dip in the pulse profile. Phase-resolved spectral analysis reveals diverse spectral variation during pulsation cycle: e.g., for an absorbed power-law model, some exhibit an (anti)-correlation between absorption and X-ray flux, while others show more intrinsic spectral variation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-05-26T22:34:24.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "deep chandra survey",
      "small magellanic cloud",
      "x-ray pulsars",
      "timing analysis",
      "absorbed power-law model"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}