Investigating the X-ray counterparts to unidentified sources in the 1000-orbit INTEGRAL/IBIS catalogue

Abstract

The latest INTEGRAL/IBIS all-sky survey lists 219 hard X-ray sources whose nature is still unknown. We report on our ongoing campaign aimed at identifying these high-energy emitters by exploiting the focusing capabilities of the X-ray Telescope (XRT, 0.2-10 keV) on board Swift, which allow an enhancement of the source localisation to arcsec level, thus facilitating the identification of the likely counterpart. By cross-correlating the list of the unidentified IBIS sources included in the latest IBIS catalogue with Swift/XRT archival data, we found a set of 14 objects, not yet reported in the literature, for which XRT data were available. We found no detection in only one case, a single X-ray association in 9 sources, and 2/3 associations in the remaining objects. We then made use of multi-waveband archives to search for counterparts at other wavelengths of these XRT detections and exploited X-ray spectral information in an attempt to determine their nature and association with the IBIS object. As a result of our analysis, we identified a single counterpart for 13 sources, although in some cases its nature/class could not be assessed on the basis of the information collected. More specifically, we found that SWIFT J0924.2-3141 and SWIFT J1839.1-5717 are absorbed AGN, while SWIFT J0800.7-4309 and 1SWXRT J230642.8+550817 are Cataclysmic Variable binary systems. Finally, we found that IGR J14059-6116 is likely associated with the Fermi source 3FGL J1405.4-6119. In the case of XMMSL1 J030715.5-545536 no XRT counterpart was detected. In all the other cases, optical/infrared spectroscopy is necessary to classify properly each X-ray counterpart and confirm their association with the INTEGRAL/IBIS detection.

16 pages, 22 figures, 4 tables. Accepted for publication in MNRAS

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Cited by in corpus (18)

• The 105 month Swift-BAT all-sky hard X-ray survey
• Advances in Understanding High-Mass X-ray Binaries with INTEGRAL and Future Directions
• INTEGRAL/IBIS 17-yr hard X-ray all-sky survey
• Discovery of the Galactic High-Mass Gamma-ray Binary 4FGL J1405.1-6119
• Optical Studies of 15 Hard X-ray Selected Cataclysmic Binaries
• Constraints to neutron-star kicks in High-Mass X-ray Binaries with Gaia EDR3
• INTEGRAL view of AGN
• 15 years of Galactic surveys and hard X-ray Background measurements
• Chandra Observations of High Energy X-ray Sources Discovered by INTEGRAL
• Classifying IGR J15038-6021 as a magnetic CV with a massive white dwarf
• Update of the INTEGRAL/IBIS AGN catalogue: deeper on the Galactic plane and wider beyond
• Field linkage and magnetic helicity density
• Investigating the true nature of three hard X-ray sources
• A multifrequency characterization of the extragalactic hard X-ray sky
• Multi-wavelength observations of the Galactic X-ray binaries IGR J20155+3827 and Swift J1713.4-4219
• SRG/ART-XC all-sky X-ray survey: Catalog of sources detected during the first year
• Measuring the precise photometric period of the intermediate polar 1RXS J230645.0+550816 (1SWXRT J230642.7+550817) based on extensive photometry
• Swift-XRT follow-up analysis of unidentified hard X-ray sources