Radio-loud AGN contribution to the Extragalactic Gamma-Ray Background

TL;DR

This paper investigates the contribution of radio-loud AGN, especially blazars, to the extragalactic gamma-ray background by constructing their luminosity functions using Fermi LAT data and modeling their evolution.

Contribution

It presents the first detailed luminosity function and evolution models for blazars based on the LAT AGN catalog, including both aligned and misaligned sources.

Findings

Blazars are significant contributors to the EGRB.

Constructed luminosity functions for FSRQs using LAT data.

Methodology for estimating contributions from misaligned blazars.

Abstract

Origin of extragalactic gamma-ray background (EGRB) is still a matter of debate. EGRB can either have truly diffuse or unresolved discrete point sources origin. Majority of the Fermi and EGRET detected identified sources are blazar. So, they are expected to be a significant contributors to the EGRB. In order to estimate their contribution to the EGRB one needs to construct their luminosity functions. Here, we examine and construct the evolution and luminosity function of blazars using first LAT AGN catalog. We consider both pure luminosity and pure density evolution models for flat spectrum radio quasars (FSRQs). We also describe the methodology to estimate the contribution from misaligned blazars to the EGRB.