Identification of newly-discovered sources belonging to the 4th IBIS catalog and to the 54 months Palermo Swift/BAT catalog

TL;DR

This paper summarizes the identification of new hard X-ray sources from the 4th IBIS and 54-month Palermo Swift/BAT catalogs, using optical spectroscopy to determine their nature.

Contribution

It presents the results of an optical spectroscopy program that successfully identified numerous sources from recent all-sky hard X-ray surveys, expanding knowledge of high-energy objects.

Findings

Identification of new sources from IBIS and Swift/BAT catalogs.

Successful optical spectroscopy campaign leading to source classification.

Preliminary results on the nature of newly-discovered high-energy sources.

Abstract

The most recent all-sky surveys performed with the INTEGRAL and SWIFT satellites allowed the detection of more than 1500 sources in hard X-rays above 20 keV. About one quarter of them has no obvious counterpart at other wavelengths and therefore could not be associated with any known class of high-energy emitting objects. Although cross-correlation with catalogues or surveys at other wavelengths (especially soft X-rays) is of invaluable support in pinpointing the putative optical candidates, only accurate optical spectroscopy can reveal the true nature of these sources. With the aim of identifying them, we started in 2004 an optical spectroscopy program which uses data from several telescopes worldwide and which proved extremely successful, leading to the identification of about 200 INTEGRAL objects and nearly 130 Swift sources. Here we want to present a summary of this identification work and an outlook of our preliminary results on identification of newly-discovered sources belonging to the 4th IBIS catalog and to the 54 months Palermo Swift/BAT catalog.