VERITAS Long-Term Observations of Hard Spectrum Blazars

TL;DR

This paper reports long-term gamma-ray observations of distant hard-spectrum blazars by VERITAS, providing insights into their spectra and the universe's diffuse extragalactic background light through gamma-ray absorption features.

Contribution

First long-term observational results of specific distant blazars by VERITAS, highlighting their spectra and implications for extragalactic background light studies.

Findings

Blazars' spectra are well fit by power laws.

Gamma-ray absorption features relate to extragalactic background light.

Observations support gamma-ray attenuation as a probe of cosmic background.

Abstract

The VERITAS collaboration has approved long-term observations on several distant, hard-spectrum blazars. We present first results from VERITAS long-term observations of 1ES1218+304, 1ES0229+200, and 1ES0414+009. Gamma-ray observations of distant, hard-spectrum blazars has emerged as an effective, indirect probe of the universe's diffuse extragalactic background light (EBL), due to the extinction of gamma-rays via the pair production interaction $\gamma_{TeV}\gamma_{EBL}\rightarrow e^{+}e^{-}$, which is expected to produce absorption features in distant gamma-ray sources. The sources presented here emit spectra that are well fit by power laws.