Mrk 421 is a high-synchrotron-peaked blazar featuring bright and persistent GeV and TeV emission. We use multi-wavelength light curves of Mrk 421 spanning 5.5 years with FACT (TeV) and Fermi LAT (GeV) in the gamma rays, Swift BAT, Swift XRT and MAXI in the X-rays, together with optical and radio data and investigate the physical processes driving the emission and variability. Observations by FACT are continuous and not triggered, so the source was found in a wide range of flux states and more than 30 flares were identified from X-rays to TeV. The light curves in TeV and X-rays feature very similar flares with rise and decay times of a few days and zero lag, characteristic for electron processes. At least two parameters per flare, the amplitude and the cut-off energy, are required to explain the observed variability. In addition, the GeV light curve leads and is strongly correlated with the optical and radio light curves as expected from SSC emitting shock propagating in a conical jet.
@article{arxiv.1908.09770,
title = {FACT -- Multi-wavelength analysis of more than 30 flares of Mrk 421},
author = {Vitalii Sliusar and Axel Arbet-Engels and Dominik Baack and Matteo Balbo and Adrian Biland and Michael Blank and Tomas Bretz and Kai Bruegge and Michael Bulinski and Jens Buss and Manuel Doerr and Daniela Dorner and Dominik Elsaesser and Dorothee Hildebrand and Karl Mannheim and Sebastian mueller and Dominik Neise and Maximilian Noethe and Aleksander Paravac and Wolfgang Rhode and Bernd Schleicher and Kevin Sedlaczek and Amit Shukla and Roland Walter and Elan von Willert},
journal= {arXiv preprint arXiv:1908.09770},
year = {2019}
}
Comments
9 pages, 3 figures, 1 table. 36th International Cosmic Ray Conference (ICRC2019), July 24th-August 1st, 2019. Madison, WI, U.S.A