Optical Identification of X-ray Sources from the 14-Year INTEGRAL All-Sky Survey

TL;DR

This study used multi-wavelength observations and optical spectroscopy to identify and classify X-ray sources from the INTEGRAL survey, revealing several as active galactic nuclei and refining their positions and properties.

Contribution

The paper provides new optical identifications and redshift measurements for INTEGRAL X-ray sources, improving positional accuracy and classification of these objects.

Findings

Six sources identified as Seyfert galaxies

Refined positions for multiple X-ray sources

Most identified sources are extragalactic

Abstract

We present the results of our optical identifications of several hard X-ray sources from the INTEGRAL all-sky survey obtained over 14 years of observations. Having improved the positions of these objects in the sky with the X-ray telescope (XRT) of the Swift observatory and the XMM-Newton observatory, we have identified their counterparts using optical and infrared sky survey data. We have obtained optical spectra for more than half of the objects from our sample with the RTT-150 and AZT-33IK telescopes, which have allowed us to establish the nature of the objects and to measure their redshifts. Six sources are shown to be extragalactic in origin and to belong to Seyfert 1 and 2 galaxies (IGR J01017+6519, IGR J08215-1320, IGR J08321-1808, IGR J16494-1740, IGR J17098-2344, IGR J17422-2108); we have failed to draw definitive conclusions about the nature of four more objects (IGR J11299-6557, IGR J14417-5533, IGR J18141-1823, IGR J18544+0839), but, judging by circumstantial evidence, they are most likely also extragalactic objects. For one more object (IGR J18044-1829) no unequivocal identification has been made.