Multiwavelength studies of hard X-ray selected sources

TL;DR

This study follows up on 148 hard X-ray sources, identifying their nature, analyzing their properties, and discovering peculiar AGN that challenge existing unified theories, using multiwavelength observations and new diagnostic tools.

Contribution

The paper provides a comprehensive multiwavelength analysis of hard X-ray sources, including the identification of peculiar AGN and the development of a new diagnostic diagram.

Findings

Identified 27 X-ray binaries and 121 AGN from 148 sources.

Performed detailed X-ray analysis on 94 AGN to assess absorption and flux.

Discovered a few peculiar AGN that challenge the unified model.

Abstract

Hard X-ray surveys like those provided by IBIS and BAT on board the INTEGRAL and Swift satellites list a significant number of sources which are unidentified and/or unclassified and which deserve multiwaveband observations to be properly characterized. In this work we have been able to follow up 148 such sources, finding 27 X-ray binaries and 121 Active Galactic Nuclei (AGN). From the AGN sample we extracted a set of 94 AGN, belonging to the INTEGRAL/IBIS and Swift/BAT surveys, for which we performed an X-ray study to determine absorption and 2-10 keV flux by means of XMM-Newton and Swift/XRT available observations. Using a new diagnostic diagram we identified a few peculiar sources which apparently do not fit within the AGN unified theory. Finally, we have compared the optical versus X-ray properties of these 94 AGN to study the optical reddening versus the X-ray absorption local to the AGN