{
  "id": "2104.12130",
  "version": "v1",
  "published": "2021-04-25T11:06:30.000Z",
  "updated": "2021-04-25T11:06:30.000Z",
  "title": "Temporal and spectral study of PKS 0208-512 during 2019-20 flare",
  "authors": [
    "Rukaiya Khatoon",
    "Raj Prince",
    "Zahir Shah",
    "Sunder Sahayanathan",
    "Rupjyoti Gogoi"
  ],
  "comment": "13 pages, 8 figures, 4 tables, submitted to MNRAS, comments are welcome",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present the temporal and spectral study of blazar PKS 0208-512, using recent flaring activity from November 2019 to March 2020, as detected by Fermi-LAT, Swift-XRT/UVOT observatories. The source was in a low ${\\gamma}$-ray flux state for a decade and started flaring in November 2019, which continues until March 2020. During the activity state, 2-days binned ${\\gamma}$-ray lightcurve shows multiple-peaks indicating sub-flares. To understand the possible physical mechanisms behind flux enhancement, a detailed temporal and spectral study has been carried out by dividing the activity into several flux-states. Timing analysis of lightcurves suggests that peaks of sub-flares have rise and decay time in days-order with flux-doubling time $\\sim$ 2-days. The 2-days binned ${\\gamma}$-ray lightcurve shows double-lognormal flux distribution. The broadband spectral energy distribution for three selected flux states can be well fitted under synchrotron, synchrotron-self-Compton (SSC) and external-Compton (EC) emission mechanisms. We obtained the physical parameters of the source and their confidence intervals through ${\\chi}^2$-statistics. Our spectral study suggests that during quiescent-state, gamma-ray spectrum can be well explained by considering the EC-scattering of IR-photons from the dusty-torus. However, gamma-ray spectra corresponding to flares demand additional target photons from broad-line-region (BLR) along with the IR. These suggest that during flares, the emission-region is close to the edge of BLR, while for quiescent-state the emission-region is away from the BLR. The best-fit results suggest that, marginal increase in the magnetic-field can result in the flux enhancement. This is possibly associated with the efficiency of particle acceleration during flaring-states as compared to quiescent-state.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-04-25T11:06:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spectral study",
      "flares demand additional target photons",
      "ray lightcurve",
      "flux enhancement",
      "gamma-ray spectrum"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}