Multi-TeV Flaring from High-energy Blazars: An Evidence of the Photohadronic Process
Abstract
High-energy peaked blazars are known to undergo episodes of flaring in GeV-TeV gamma-rays involving different timescales. This flaring mechanism is not well understood, despite long-term simultaneous multiwavelength observations. These gamma-rays en route to Earth undergo attenuation by the extragalactic background light. Using the photohadronic model, where the seed photons follow a power-law spectrum and a template extragalactic background light model, we derive a simple relation between the observed multi-TeV gamma-ray flux and the intrinsic flux with a single parameter. We study 42 flaring epochs of 23 blazars and excellent fits to most of the observed spectra are obtained, strengthening the photohadronic origin of multi-TeV gamma-rays. We can also constrain the power spectrum of the seed photons during the flaring period. Stringent bounds on the blazars of unknown redshifts, whose multi-TeV flaring spectra are known, can be placed using the photohadronic model.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2019
- DOI:
- 10.3847/2041-8213/ab43c7
- arXiv:
- arXiv:1909.10634
- Bibcode:
- 2019ApJ...884L..17S
- Keywords:
-
- High energy astrophysics;
- Blazars;
- Gamma-rays;
- Relativistic jets;
- BL Lacertae objects;
- 739;
- 164;
- 637;
- 1390;
- 158;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Phenomenology
- E-Print:
- 11 pages, 4 figures, supplementary material, 14 pages, 11 figures, accepted for publication in APJ Letters