{
  "id": "1001.0356",
  "version": "v1",
  "published": "2010-01-03T09:00:31.000Z",
  "updated": "2010-01-03T09:00:31.000Z",
  "title": "Suzaku Monitoring of the Iron K Emission Line in the Type 1 AGN NGC 5548",
  "authors": [
    "Yuan Liu",
    "Martin Elvis",
    "Ian M. McHardy",
    "Dirk Grupe",
    "Belinda J. Wilkes",
    "James Reeves",
    "Nancy Brickhouse",
    "Yair Krongold",
    "Smita Mathur",
    "Takeo Minezaki",
    "Fabrizio Nicastro",
    "Yuzuru Yoshii",
    "Shuang Nan Zhang"
  ],
  "comment": "33 pages, 9 figures, 4 tables, accepted for publication in the Astrophysical Journal",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present 7 sequential weekly observations of NGC 5548 conducted in 2007 with the \\textit{Suzaku} X-ray Imaging Spectrometer (XIS) in the 0.2-12 keV band and Hard X-ray Detector (HXD) in 10-600 keV band. The iron K$\\alpha$ line is well detected in all seven observations and K$\\beta$ line is also detected in four observations. In this paper, we investigate the origin of the Fe K lines using both the width of the line and the reverberation mapping method. With the co-added XIS and HXD spectra, we identify Fe K$\\alpha$ and K$\\beta$ line at 6.396$_{-0.007}^{+0.009}$ keV and 7.08$_{-0.05}^{+0.05}$ keV, respectively. The width of line obtained from the co-added spectra is 38$_{-18}^{+16}$ eV ($\\textrm{FWHM}=4200_{-2000}^{+1800}$ km/s) which corresponds to a radius of 20$_{-10}^{+50}$ light days, for the virial production of $1.220\\times10^7$ M$_{\\odot}$ in NCG 5548. To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping method, we compare the observed light curves of Fe K$\\alpha$ line with the predicted ones, which are obtained by convolving the continuum light curve with the transfer functions in a thin shell and an inclined disk. The best-fit result is given by the disk case with $i=30^\\circ$ which is better than a fit to a constant flux of the Fe K line at the 92.7% level (F-test). We find that the emitting radius obtained from the light curve is 25-37 light days, which is consistent with the radius derived from the Fe K line width. Combining the results of the line width and variation, the most likely site for the origin of the narrow iron lines is 20-40 light days away from the central engine, though other possibilities are not completely ruled out. (abridged)",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-01-03T09:00:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "emission line",
      "agn ngc",
      "light curve",
      "suzaku monitoring",
      "reverberation mapping method"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/710/2/1228",
      "journal": "The Astrophysical Journal",
      "year": 2010,
      "month": "Feb",
      "volume": 710,
      "number": 2,
      "pages": 1228
    },
    "note": {
      "typesetting": "TeX",
      "pages": 33,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 841703,
      "adsabs": "2010ApJ...710.1228L"
    }
  }
}