{
  "id": "1707.05536",
  "version": "v1",
  "published": "2017-07-18T09:25:55.000Z",
  "updated": "2017-07-18T09:25:55.000Z",
  "title": "A deep X-ray view of the bare AGN Ark 120. III. X-ray timing analysis and multiwavelength variability",
  "authors": [
    "Andrew Lobban",
    "Delphine Porquet",
    "James Reeves",
    "Alex Markowitz",
    "Emanuele Nardini",
    "Nicolas Grosso"
  ],
  "comment": "25 pages, 24 figures, 6 tables",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present the spectral/timing properties of the bare Seyfert galaxy Ark 120 through a deep ~420ks XMM-Newton campaign plus recent NuSTAR observations and a ~6-month Swift monitoring campaign. We investigate the spectral decomposition through fractional rms, covariance and difference spectra, finding the mid- to long-timescale (~day-year) variability to be dominated by a relatively smooth, steep component, peaking in the soft X-ray band. Additionally, we find evidence for variable FeK emission red-ward of the FeK-alpha core on long timescales, consistent with previous findings. We detect a clearly-defined power spectrum which we model with a power law with a slope of alpha ~ 1.9. By extending the power spectrum to lower frequencies through the inclusion of Swift and RXTE data, we find tentative evidence of a high-frequency break, consistent with existing scaling relations. We also explore frequency-dependent Fourier time lags, detecting a negative ('soft') lag for the first time in this source with the 0.3-1 keV band lagging behind the 1-4 keV band with a time delay of ~900s. Finally, we analyze the variability in the optical and UV bands using the Optical/UV Monitor on-board XMM-Newton and the UVOT on-board Swift and search for time-dependent correlations between the optical/UV/X-ray bands. We find tentative evidence for the U-band emission lagging behind the X-rays with a time delay of 2.4 +/- 1.8 days, which we discuss in the context of disc reprocessing.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-07-18T09:25:55.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "deep x-ray view",
      "bare agn ark",
      "x-ray timing analysis",
      "multiwavelength variability",
      "power spectrum"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 25,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}