Bethe-Heitler cascades as a plausible origin of hard spectra in distant TeV blazars

Y. G. Zheng, C. Y. Yang, S. J. Kang

Context. Very high-energy (VHE) $\gamma$-ray measurements of distant TeV blazars can be nicely explained by TeV spectra induced by ultra high-energy cosmic rays. Aims. We develop a mode…