Emitting electrons and source activity in Markarian 501

Abstract

We study the variation of the broad-band spectral energy distribution (SED) of the BL Lac object Mrk 501 as a function of source activity, from quiescent to flaring. Through chi-square-minimization we model eight simultaneous SED datasets with a one-zone Synchrotron-Self-Compton (SSC) model, and examine how model parameters vary with source activity. The emerging variability pattern of Mrk 501 is complex, with the Compton component arising from gamma-electron scatterings that sometimes are (mostly) Thomson and sometimes (mostly) extreme Klein-Nishina. This can be seen from the variation of the Compton to synchrotron peak distance according to source state. The underlying electron spectra are faint/soft in quiescent states and bright/hard in flaring states. A comparison with Mrk 421 suggests that the typical values of the SSC parameters are different in the two sources: however, in both jets the energy density is particle dominated in all states.

8 pages, 4 figures, 1 table; accepted for publication in ApJ

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Cited by in corpus (21)

• Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
• Relativistic Jets in Active Galactic Nuclei und Microquasars
• Multiwavelength observations of Mrk 501 in 2008
• First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign
• Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
• The physical properties of Fermi BL Lac objects jets
• Long-term study of Mkn 421 with the HAGAR Array of Telescopes
• H.E.S.S and Fermi-LAT discovery of gamma rays from the blazar 1ES 1312-423
• Very High Energy outburst of Markarian 501 in May 2009
• Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes
• Discovery of very high energy gamma-ray emission from the blazar 1ES 0033+595 by the MAGIC telescopes
• MAGIC detection of very high energy gamma-ray emission from the low-luminosity blazar 1ES 1741+196
• Verification of the diffusive shock acceleration in Mrk 501
• Emitting Electron Spectra and Acceleration Processes in the Jet of PKS 0447-439
• Polarimetric Tomography of Blazar Jets
• Exploring the Variability of the Flat Spectrum Radio Source 1633+382. II: Physical Properties
• Establishing the Spectral Turnover of Blazar PKS 2155-304 as an Outcome of Radiative Losses
• Do radiative losses determine the characteristic emission of the blazar Mkn 421?
• Very High-energy Gamma-Ray Episodic Activity of Radio Galaxy NGC 1275 in 2022-2023 Measured with MACE
• Using the Markov Chain Monte Carlo method to study the physical properties GeV-TeV BL Lac objects
• Evidence of a lepto-hadronic two-zone emission in flare states