Abstract Details
| Name: Ritaban Chatterjee Affiliation: Presidency University, Kolkata Conference ID: ASI2019_556 Title : Detailed Time Variability Properties of Blazars Using AstroSat Authors and Co-Authors : Author: Ritaban Chatterjee Co-authors: Agniva Roychowdhury (Presidency University, University of Maryland Baltimore County), Sagnick Mukherjee (Presidency University), Souradip Bhattacharya (Presidency University), Ritesh Ghosh (Visva-Bharati University) Abstract Type : Invited Abstract Category : Plenary Abstract : While the X-ray time variability at hours to years timescale of a large sample of Seyfert galaxies have been carried out using observations from RXTE and XMM-Newton, similar study for blazars is not very common. We have used 5-day-long light curves of the blazar Mrk 421 from AstroSat-SXT and AstroSat-LAXPC, along with archival observations from Swift to calculate very detailed power spectra, and inter-band correlation and time lags. We find that the power spectrum has a break, i.e., the slope changes at a certain timescale. This property is similar to Seyfert galaxies and Galactic black hole X-ray binaries (BHXRBs) where such break is present in many cases and the break timescale is related to the BH mass. However, in those sources the X-rays are from the accretion disk-corona region while in the blazars it is from the jet. Therefore, a similar power spectrum may indicate that changes in the accretion disk, which may be the source of the break timescale are translating into the jet, where the X-rays are produced. We model the non-thermal emission from the jet assuming certain modes of its connection with the disk to test if the resultant variability produces power spectra similar to that obtained from the data. Furthermore, we correlate the X-ray variability at multiple energy bands and calculate the phase spectrum and coherence function. The results of these analyses are consistent with the properties of non-thermal emission in blazars jets. We compare the short-timescale (hr-days) X-ray power spectrum of Mrk 421 with those obtained from similar archival data to test if the shape and slope of the power spectra stay stationary at the timescale of years. |