Modeling the hard TeV spectra of blazars 1ES 0229+200 and 3C 66A with an internal absorption scenario

TL;DR

This paper explores an internal gamma-ray absorption model involving proton synchrotron radiation in magnetized blobs to explain the unusually hard TeV spectra of blazars 1ES 0229+200 and 3C 66A, fitting multi-band observations.

Contribution

It demonstrates that internal absorption of proton-synchrotron gamma-rays can self-consistently explain the hard spectra of these blazars with reasonable parameters.

Findings

The model fits the observed spectra of 1ES 0229+200 and 3C 66A.

It requires modest energy budgets for the proton populations.

The scenario is consistent across keV, GeV, and TeV energy bands.

Abstract

We study the applicability of the idea of internal absorption of gamma-rays produced through synchrotron radiation of ultrarelativistic protons in highly magnetized blobs to 1ES 0229+200 and 3C 66A, the two TeV blazars which show unusually hard intrinsic gamma-ray spectra after being corrected for the intergalactic absorption. We show that for certain combinations of reasonable model parameters, even with quite modest energy requirements, the scenario allows a self-consistent explanation of the non-thermal emission of these objects in the keV, GeV, and TeV energy bands.