X-ray intraday variability of the TeV blazar Mrk 421 with {\it XMM-Newton}

Abstract

Highly variable Markarian 421 is a bright high synchrotron energy peaked blazar showing wide featureless non-thermal spectrum making it a good candidate for our study of intraday flux and spectral variations over time. We analyse its X-ray observations of over 17 years taken with the EPIC-PN instrument to probe into the intraday variability properties. The photon energy band of 0.3 - 10.0 keV, and its sub-bands, soft 0.3-2.0 keV and hard 2.0-10.0 keV. To examine flux variability, fractional variability amplitude and the minimum variability timescale have been calculated. We also probed into the spectral variability by studying hardness ratio for each observation and the correlation between the two energy bands using discrete correlation function and inspecting the normalized light curves. The parameters obtained from these methods have been studied for any correlation or non-random trends. From this work, we speculate on the constraints for possible particle acceleration and emission processes in the jet, for better understanding of the processes involving a turbulent behaviour except of shocks. A positive discrete correlation function between the two sub-bands indicates the role of the same electron population in the emission of photons in the two bands. The correlation between the parameters of flux variability and parameters of spectral variation and lags in sub-energy bands provide the constraints to be considered for any modelling of emission processes.

Accepted in APJS on 31 May 2022; Online supplementary material of paper placed in ancillary material on arxiv

References in corpus (13)

• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010
• Signatures of synchrotron emission and of electron acceleration in the X-ray spectra of Mrk 421
• X-ray Intraday Variability of Five TeV Blazars with NuSTAR
• Unravelling the complex behavior of Mrk 421 with simultaneous X-ray and VHE observations during an extreme flaring activity in April 2013
• INTEGRAL observations of the blazar Mrk 421 in outburst (Results of a multi-wavelength campaign)
• Multi-wavelength Intra-day Variability and Quasi-periodic Oscillation in Blazars
• Disentangling the synchrotron and Inverse Compton variability in the X-ray emission of the intermediate BL Lac object S5 0716+71
• Blazar variability power spectra from radio up to TeV photon energies: Mrk 421 and PKS 2155-304
• X-ray Intraday Variability of the TeV Blazar PKS 2155-304 with Suzaku During 2005-2014
• Multi-band Variability of the TeV Blazar PG 1553+113 with XMM-Newton
• X-ray timing and spectral variability properties of blazars S5 0716+714, OJ 287, Mrk 501, and RBS 2070
• X-ray Intraday Variability and Power Spectral Density Profiles of the Blazar 3C 273 with XMM-Newton during 2000-2021

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• X-ray Activity Variations and Coronal Abundances of the Star-Planet Interaction candidate HD 179949
• Multi-band optical variability of the blazar OP 313 in the outburst state during 2024-2025
• X-ray Fourier lag-frequency spectra modulated by stochastic turbulent acceleration in the jets of high-frequency-peaked BL Lac
• NICER Perspective on TeV Blazar Mrk~421: X-ray Variability and Particle Acceleration