Revealing the nature of new unidentified INTEGRAL sources

TL;DR

This paper uses optical spectroscopy and multiwavelength data to classify 25 previously unidentified high-energy sources detected by INTEGRAL, enhancing our understanding of their nature.

Contribution

It presents the classification of 25 new INTEGRAL sources using optical spectroscopy, expanding the catalog of identified high-energy objects.

Findings

25 sources classified through optical spectroscopy

Improved understanding of the nature of INTEGRAL sources

Contributes to the ongoing identification program since 2004

Abstract

Since its launch on October 2002, the INTEGRAL satellite has revolutionized our knowledge of the hard X-ray sky thanks to its unprecedented imaging capabilities and source detection positional accuracy above 20 keV. Nevertheless, many of the newly-detected sources in the INTEGRAL sky surveys are of unknown nature. However, the combined use of available information at longer wavelengths (mainly soft X-rays and radio) and of optical spectroscopy on the putative counterparts of these new hard X-ray objects allows pinpointing their exact nature. Continuing our long-standing program running since 2004 (and with which we identified more than 100 INTEGRAL objects) here we report the classification, through optical spectroscopy, of 25 unidentified high-energy sources mostly belonging to the recently published 4th IBIS survey.