Probing blazar jet structures using XMM Newton

Adithiya Dinesh

The X-ray emission from blazars has been widely investigated using several space telescopes. In this work, we explored statistical properties of the X-ray variability in the blazars 3C 273, Mrk 401, PKS 2155-304, etc using the archival observations from the XMM-Newton telescope between the period 2000–2020. Several methods of timing and spectral analyses including
fractional variability, power spectral density analyses, and countrate distribution were performed. Few spectral models were fitted to the observations as well as estimated the hardness ratio. The results show that the sources are moderately variable within the intra-day timescale. Some of the sources exhibited a clear bi-modal pattern in their countrate distribution revealing possible indication of two distinct countrate states, that is, hard and soft countrate states. Furthermore, the spectra of the sources were fitted with single power-law, broken power-law, log-parabolic and black-body+log-parabolic models. We conclude that for most of the observations log-parabolic model was the best fit. However, for 3C 273 a logparabolic added with blackbody model gave the best fit indicating we receive some emission from the accretion disk. The power spectral density analysis revealed the variable nature of PSD slopes in the source light curves. The results of this analysis could indicate the non-stationary nature of the blazar processes on intra-day timescales.