Bulletin of ANPA

Abstract submitted to ANPA Conference July 14–16, 2023

Volume 5, Number 1

Astronomy /Space Science /Cosmo Science/ Atmospheric

Abstract ID: ANPA2023-N00012

Abstract:

ANPA2023-N00012: Constraining X-ray variability of blazars BL Lacertae, Mrk 421, and Mrk 501 using Swift-XRT

Authors:

• Aayush Gautam; Birendra Multiple Campus, Tribhuvan University, Nepal

• Gopal Bhatta;

• Angel Bashyal;

• Ashok Chaudhary;

• Bikash Thapa;

• Hari Ram Krishna Gauli;

• Keshab Chaudhary;

• Dinesh Bishwakarma;

• Vivek Reddy Pininti;

• Devendra Raj Upadhyay;

• Yogesh Singh Maharjan;

• Rajendra Adhikari;

Blazars, a subclass of active galactic nuclei, represent one of the most luminous sources in the Universe. The sources featuring relativistic jets aligned closely to the line of sight are believed to be powered by supermassive black holes at the center. Blazars exhibit multi-wave band flux variability in diverse timescales, that is, from a few minutes to decades. In this work, we present a study of the long-term variability properties of three blazars BL Lacertae, Mrk 421, and Mrk 501 using 17-year (2005 - 2022) long archival observations from the XRT telescope of the Neil Gehrels Swift Observatory (Swift-XRT). We applied various methods of timing analysis including fractional variability, count-rate distributions, and power spectral density (PSD) to investigate the temporal variability in the 0.3-10 KeV energy range. In addition, we studied the evolution of the hardness ratio in the same period. The results indicate that the X-ray light curves are highly variable with a fractional variability of 83 ± 1%. The PSD is consistent with a power law. and the probability density function (PDF) of the count rates is best represented by heavy-tailed log-normal. Models involving shocks in the jets and magnetic reconnection events in a turbulent jet can be used to explain the observed results.

To cite this abstract, use the following reference: https://anpaglobal.org/conference/2023/ANPA2023-N00012