Chasing extreme blazars with INTEGRAL

TL;DR

This paper investigates high-redshift blazars detected by INTEGRAL, highlighting their extreme properties, comparing their characteristics with gamma-ray selected blazars, and reporting new detections within this population.

Contribution

It presents a sample of 12 high-redshift blazars detected by INTEGRAL, including 3 new identifications, and compares their properties with Fermi-selected blazars, emphasizing their extreme nature.

Findings

12 high-redshift blazars detected by INTEGRAL, including 3 new sources

Comparison of INTEGRAL and Fermi blazar samples reveals differences in spectral properties

High-redshift blazars exhibit extreme jet and accretion disk characteristics

Abstract

Within the blazar population, hard X-ray selected objects are of particular interest as they tend to lie at each end of the blazar sequence. In particular, flat spectrum radio quasars located at high redshifts display the most powerful jets, the largest black hole masses and the most luminous accretion disks: their spectral energy distribution has a Compton peak in the sub-MeV region which favours their detection by instruments like INTEGRAL/IBIS and Swift/BAT. These sources are even more extreme than blazars selected in other wavebands, like, for example, the gamma-ray range explored by Fermi. Here we report on a sample of 12 high redshift blazars detected so far by INTEGRAL, including 3 newly identified objects. Some properties of the combined IBIS/BAT sample of high redshift blazars (z>2) are also compared to those of a similar similar sample obtained by Fermi.