Astronomy and Astrophysics
Aims: By modelling the interactions of beam electrons (positrons) with hydrogen and helium recombination-line photons, we seek to describe the spectral signature of beam-driven cascades in the broad emission-line region of blazar jets.
Methods: Employing coupled kinetic equations for electrons (positrons) and photons including an escape term, we numerically obtained their steady-state distributions and the escaping photon spectrum.
Results: We find that cascade emission resulting from beam interactions can produce a narrow spectral feature at TeV energies. Indications of such an intermittent feature, which defies an explanation in the standard shock-in-jet scenario, have been found at ≈ 4σ confidence level at an energy of ≈ 3 TeV in the spectrum of the blazar Mrk 501.
Conclusions: The energetic requirements for explaining the intermittent 3 TeV bump with the beam-interaction model are plausible: Gap discharges that lead to multi-TeV beam electrons (positrons) carrying ≈ 0.1% of the Blandford-Znajek luminosity, which interact with recombination-line photons from gas clouds that reprocess ≈ 1% of the similar accretion luminosity are required.
El Grupo de Astrofísica de Partículas del IAC participa activamente en tres grandes colaboraciones internacionales de astrofísica de muy altas energías: AMS (Alpha Magnetic Spectrometer), los telescopios de radiación Cherenkov MAGIC I y II, y el Cherenkov Telescope Array (CTA). AMS es un detector de partículas diseñado para operar en el espacio, a