IGR J12319-0749: evidence for another extreme blazar found with INTEGRAL
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 × 10-12 erg cm-2 s-1, is spatially coincident with an active galactic nucleus (AGN) at redshift z = 3.12. The broad-band continuum, obtained by combining XRT and IBIS data, is flat (Γ = 1.3) with evidence for a spectral break around 25 keV (100 keV in the source restframe). X-ray observations indicate flux variability, which is also supported by a comparison with a previous ROSAT measurement. IGR J12319-0749 is also a radio-emitting object likely characterised by a flat spectrum and high radio loudness; optically it is a broad-line emitting object with a massive black hole (2.8 × 109 solar masses) at its centre. The source spectral energy distribution is similar to another high-redshift blazar, 225155+2217 at z = 3.668: both objects are bright, with a high 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.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2012
- DOI:
- 10.1051/0004-6361/201219243
- arXiv:
- arXiv:1205.3037
- Bibcode:
- 2012A&A...543A...1B
- Keywords:
-
- gamma rays: general;
- X-rays: galaxies;
- galaxies: active;
- X-rays: individuals: IGR J12319;
- 0749;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 4 figures, 1 table. Accepted for publication in A&