English

Temporary EHBL-like behavior of Markarian 501 during July 2014 VHE flaring

High Energy Astrophysical Phenomena 2026-04-08 v2 High Energy Physics - Phenomenology

Abstract

Markarian 501, a BL Lac object well-known as a high energy gamma-ray source, has exhibited several epochs of very high energy (VHE) gamma-ray flaring events when its synchrotron peak frequency shifted above 101710^{17} Hz, a signature of extreme behavior. From July 16 to July 31, 2014 such flaring events were observed for 15 days by various telescopes. On July 19 (MJD 56857.98), the X-ray outburst from the source was at its highest and on the same day an intriguing narrow peak-like feature around 3 TeV was observed by the MAGIC telescopes, a feature inconsistent with standard interpretations. Using the well-known two-zone photohadronic model, we study these VHE gamma-ray spectra on a day-by-day basis and offer explanation. Our two-zone photohadronic scenario shows that, on MJD 56857.98, the peak-like feature appears at a cutoff energy of Eγc=3.18E^c_{\gamma}=3.18 TeV. Below this energy the VHE spectrum increases slowly and is in high emission state. However, for Eγc>3.18E^c_{\gamma}\, > 3.18 TeV, the spectrum falls faster, resulting in a mild peak-like feature, not prominent enough as claimed by the MAGIC collaboration.

Keywords

Cite

@article{arxiv.2502.07940,
  title  = {Temporary EHBL-like behavior of Markarian 501 during July 2014 VHE flaring},
  author = {Sarira Sahu and A. U. Puga Oliveros and D. I. Páez-Sánchez and G. Sánchez-Colón and Subhash Rajpoot and M. E. Iglesias Martínez and José Guerra Carmenate and P. Fernández de Córdoba and Gaetano Lambiase},
  journal= {arXiv preprint arXiv:2502.07940},
  year   = {2026}
}

Comments

12 pages, 7 figures, 1 table