Observable spectral and angular distributions of γ-rays from extragalactic ultrahigh energy cosmic ray accelerators: the case of extreme TeV blazars

ABSTRACT Ultrahigh energy protons and nuclei from extragalactic cosmic ray sources initiate intergalactic electromagnetic cascades, resulting in observable fluxes of γ-rays the GeV–TeV domain. The total spectrum such cascade hadronic nature is significantly harder than one usually expected blazars. spectra some known as ‘extreme TeV blazars’ could be well-described by this ‘intergalactic model’ (IHCM). We calculate shape point-like spectrum, well angular distibution γ-rays, for first time taking into account effect primary proton deflection filaments galaxy clusters magnetic field assuming model Dolag et al. (2005). present estimates width γ-ray distribution derived simple geometrical considerations. also employ a hybrid code to compute spectral distributions γ-rays. at multi-TeV energies much softer averaged over all values angle. presence high-energy cutoff extreme blazars framework IHCM facilitate future searches new physics processes that enhance apparent transparency Universe (for instance, γ → ALP oscillations). greater or comparable extent point spread function next-generation telescopes.