GeV-TeV Blazar Population Studies

TL;DR

This study combines Fermi-LAT and TeV observations to analyze high-energy emission from over 30 blazars, revealing complex spectral features and potential internal absorption in some sources.

Contribution

First comprehensive spectral analysis of blazars combining Fermi-LAT and TeV data, highlighting the need for complex spectral models.

Findings

Hints of absorption features in low synchrotron-peaked BL Lacs

Simple power laws insufficient to describe spectra

Complex spectral shapes are required for accurate modeling

Abstract

The synergy between the Fermi-LAT and ground-based Cherenkov telescope arrays gives us the opportunity for the first time to characterize the high energy emission (100 MeV - 10 TeV) from more than 30 blazars. In this study we performed a Fermi-LAT spectral analysis for all TeV-detected blazars and combined it with archival TeV spectra. Our results for low synchrotron-peaked BL Lacs (LBL) show hints of absorption features in the GeV band that could be interpreted as internal opacity at the source. We note that simple or broken power laws cannot describe all the observed GeV-TeV spectra and more complex spectral shapes seem required.