The nature of the intrinsic spectra from the VHE emission of H 2356-309 and 1ES 1101-232

TL;DR

This study analyzes VHE gamma-ray emissions from H 2356-309 and 1ES 1101-232, using models to estimate their intrinsic spectra and constrain the extragalactic background light based on observational data.

Contribution

It applies the photohadronic model with two EBL templates to fit observed spectra and predict intrinsic emissions, providing insights into the EBL and intrinsic spectra of these blazars.

Findings

Good fit of VHE spectra with the models

Intrinsic spectrum of H 2356-309 is flat

Intrinsic spectrum of 1ES 1101-232 is mildly harder than 2

Abstract

The VHE emission from the HBLs H 2356-309 and 1ES 1101-232 were observed by HESS telescopes during 2004--2007. Particularly the observation in 2004 from H 2356-309 and during 2004--2005 from 1ES 1101-232 were analyzed to derive strong upper limits on the EBL which was found to be consistent with the lower limits from the integrated light of resolved galaxies. Here we have used the photohadronic model corroborated by two template EBL models to fit the observed VHE gamma-ray data from these two HBLs and to predict their intrinsic spectra. We obtain very good fit to the VHE spectra of these two HBLs. However, the predicted intrinsic spectra are different for each EBL model. For the HBL H 2356-309, we obtain a flat intrinsic spectrum and for 1ES 1101-232 the spectrum is mildly harder than 2 but much softer than 1.5.