Bethe–Heitler Cascades and Hard Gamma-Ray Spectra in Flaring TeV Blazars: 1ES 0414009 and 1ES 1959650
Year: 2025
Type: article
Abstract: Blazars are a subclass of active galactic nuclei (AGNs) with relativistic jets aligned closely to the observer’s line of sight, producing non-thermal spectral energy distributions (SEDs) characterized by two broad components: a low-energy peak (radio to UV/X-rays) and a high-energy peak (X-rays to gamma rays). While the low-energy emission is attributed to synchrotron radiation from relativistic electrons in the jet, the origin of the high-energy component remains debated, with both leptonic and hadronic processes under consideration. In this work, we present updated models of the spectral energy distributions (SEDs) for two high-frequency-peaked BL Lac objects (HBLs): 1ES 0414+009 and 1ES 1959+650. The hard gamma-ray spectra observed during their flaring states suggest the presence of an additional emission component beyond the standard synchrotron self-Compton (SSC) scenario. We explore the possibility that this hard gamma-ray emission arises from inverse Compton (IC) scattering by Bethe-Heitler pairs produced along the line of sight, pointing to a more complex high-energy emission mechanism in these sources.
Source: Universe
Institutions: Universidade Federal de Campina Grande, Universidade de São Paulo, Universidade Estadual de Londrina, Universidade Tecnológica Federal do Paraná, Universidade Federal da Integração Latino-Americana, Max Planck Institute for Nuclear Physics, Universidade Federal do Espírito Santo, Universidade Federal do Paraná
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,930
Awards: Cherenkov Telescope Array: construction and first discoveries, G116629194, G2383303383, G2472337552, G3036346570, G338262266, G3828120467, G4447602464, G4574909456, G4998824924, G5076457803, G5181231567, G6438247056, G6815844370, G6832782071, G7852917155, G7891554024, Investigation of spectral energy distribution of blazars detected in gamma rays, G8530449079, G8672097652
OpenAlex ID: W4410966639