Searching for AGNs among unidentified INTEGRAL sources

TL;DR

This paper introduces a new multi-wavelength cross-correlation method to identify Active Galactic Nuclei among unidentified INTEGRAL sources, successfully classifying several sources as AGNs or related objects.

Contribution

The paper presents a novel approach combining infrared, radio, X-ray, and optical data to efficiently identify AGNs among INTEGRAL sources, validated on a sample of eight sources.

Findings

Seven sources were identified or likely identified as AGNs.

Three sources confirmed as AGNs based on multi-wavelength data.

One source classified as a starburst galaxy, potential spurious association.

Abstract

We report on a new method to identify Active Galactic Nuclei (AGN) among unidentified INTEGRAL sources. This method consists of cross-correlating unidentified sources listed in the fourth IBIS Survey Catalogue first with infrared and then with radio catalogues and a posteriori verifying, by means of X-ray and optical follow up observations, the likelihood of these associations. In order to test this method, a sample of 8 sources has been extracted from the fourth IBIS Catalogue. For 7 sources of the sample we obtained an identification, whereas the last one (IGR J03103+5706) has insufficient information for a clear classification and deserves more in-depth study. We identified three objects (IGR J08190-3835, IGR J17520-6018, IGR J21441+4640) as AGNs and suggest that three more (IGR J00556+7708, IGRJ17219-1509, IGR J21268+6203) are likely active galaxies on the basis of their radio spectra, near-infrared photometry and location above the Galaxy plane. One source (IGR J05583-1257) has been classified as a starburst galaxy but it might have been spuriously associated with the INTEGRAL detection.