IGR J12319-0749: evidence for another extreme blazar found with INTEGRAL

TL;DR

This paper reports the discovery and analysis of IGR J12319-0749, a high-redshift blazar detected by INTEGRAL, exhibiting extreme properties such as high luminosity, spectral break, and variability, making it one of the most distant blazars observed in hard X-rays.

Contribution

The paper presents the identification and detailed spectral analysis of a new high-redshift blazar detected with INTEGRAL, highlighting its extreme characteristics and significance among distant gamma-ray sources.

Findings

Detected a new high-redshift blazar at z=3.12 with INTEGRAL.

Observed spectral break around 25 keV in the source frame.

Identified flux variability and high radio loudness.

Abstract

We report on the identification of a new soft gamma-ray source, IGR J12319-0749, detected with the IBIS imager on board the INTEGRAL satellite. The source, which has an observed 20-100 keV flux of ~8.3 x 10^{-12} erg cm^{-2} s^{-1}, is spatially coincident with an AGN at redshift z=3.12. The broad-band continuum, obtained by combining XRT and IBIS data, is flat (Gamma ~ 1.3) with evidence for a spectral break around 25 keV (100 keV in the source rest frame). X-ray observations indicate flux variability which is further supported by a comparison with a previous ROSAT measurement. IGR J12319-0749 is also a radio emitting object likely characterized by a flat spectrum and high radio loudness; optically it is a broad-line emitting object with a massive black hole (2.8 x 10^{9}$ solar masses) at its center. The source Spectral Energy Distribution is similar to another high redshift blazar, 225155+2217 at z=3.668: both objects are bright, with a large accretion disk luminosity and a Compton peak located in the hard X-ray/soft gamma-ray band. IGR J12319-0749 is likely the second most distant blazar detected so far by INTEGRAL.