Abstract Details
| Name: SITHA K JAGAN Affiliation: Department of Physics, University of Calicut, Malappuram-673635, India Conference ID: ASI2018_1676 Title : Interpretating the synchrotron spectral curvature of PKS 2155-304 Authors and Co-Authors : S.Sahayanathan; Astrophysical Sciences Division, Bhabha Atomic Research centre, Mumbai-400085, India, R. Misra; Inter-University Centre for Astronomy and Astrophysics, Post Bag4, Ganeshkhind, Pune-411, C. D. Ravikumar; Department of Physics, University of Calicut, Malappuram-673635, India; K. Jeena; Department of Physics, Providence Womens College, Malaparamba, Calicut-673009, India Abstract Type : Contributed Talk Abstract Category : Extragalactic astronomy Abstract : Blazars are the class of radio loud AGN with their relativistic jets aligned close to the line of sight of the observer. PKS 2155-304 is a BL Lac sub-division of blazars with no emission/absorbtion line features. The low energy emission, extending from radio-to-X-ray energies, are generally attributed to synchrotron radiation from a broken power-law electron distribution losing its energy in the jet magnetic field. We analyse the X-ray observation of PKS 2155-304 by XMM-Newton, spanning over 20 years, and supplement this with simultaneous Optical/UV fluxes of the source from Optical Monitor(OM) observations. The difference in the energy indices of the underlying particle distribution, inferred from these Optical/UV and X-ray spectra, are found to be larger than one. This suggests, the resulting broken power-law distribution cannot be obtained through simple synchrotron cooling of a power-law electron distribution. Here, we show such difference in the photon spectral indices can be naturally obtained through synchrotron cooling of a log-parabola particle distribution. In addition, we interpret this particle distribution as a result of an energy dependent particle escape from the main acceleration region. |