Obscured High Mass X-Ray Binaries and Supergiant Fast X-ray Transients: Infrared Observations of INTEGRAL Sources

TL;DR

This study uses multi-wavelength infrared observations to characterize two newly identified classes of high-energy binary systems from INTEGRAL data, revealing their obscured nature and transient behaviors.

Contribution

It provides the first comprehensive infrared observational analysis of 21 INTEGRAL sources, distinguishing between obscured high-energy sources and supergiant fast X-ray transients.

Findings

Obscured sources are enshrouded by dust and cold gas.

Supergiant fast X-ray transients exhibit transient X-ray activity.

Infrared observations help classify and understand these binary systems.

Abstract

A new type of high-energy binary system has been revealed by the INTEGRAL satellite. These sources are being unveiled by means of multi-wavelength optical, near- and mid-infrared observations. Among these sources, two distinct classes are appearing: the first one is constituted of intrinsically obscured high-energy sources, of which IGR J16318-4848 seems to be the most extreme example. The second one is populated by the so-called supergiant fast X-ray transients, with IGR J17544-2619 being the archetype. We report here on multi-wavelength optical to mid-infrared observations of a sample constituted of 21 INTEGRAL sources. We show that in the case of the obscured sources our observations suggest the presence of absorbing material (dust and/or cold gas) enshrouding the whole binary system. We finally discuss the nature of these two different types of sources, in the context of high energy binary systems.