Distribution of High-Mass X-ray Binaries in the Milky Way

TL;DR

This study analyzes the spatial distribution of High-Mass X-ray Binaries in the Milky Way using new observational data, spectral fitting, and correlation with star-forming regions to understand their formation, evolution, and environmental influences.

Contribution

It introduces a novel spectral energy distribution fitting method to determine HMXB distances and absorption, and examines their clustering with star-forming complexes and spiral arm offsets.

Findings

HMXBs are clustered with star-forming complexes within 0.3 kpc.

HMXBs are typically separated by about 1.7 kpc from each other.

The study constrains the age and migration distances of HMXBs due to supernova kicks.

Abstract

Observations of the high energy sky, particularly with the INTEGRAL satellite, have quadrupled the number of supergiant X-ray Binaries observed in the Galaxy, and revealed new populations of previously hidden High Mass X-ray Binaries (HMXBs), raising new questions about their formation and evolution. The number of detected HMXBs of different types is now high enough to allow us to carry out a statistical analysis of their distribution in the Milky Way. For the first time, we derive the distance and absorption of a sample of HMXBs using a Spectral Energy Distribution fitting procedure, and we examine the correlation with the distribution of Star Forming Complexes (SFCs) in the Galaxy. We show that HMXBs are clustered with SFCs with a typical cluster size of 0.3 +/- 0.05 kpc and a characteristic distance between clusters of 1.7 +/- 0.3 kpc. Furthermore, we present an investigation of the expected offset between the position of spiral arms and HMXBs, allowing us to constrain age and migration distance due to supernova kick for 13 sources. These new methods will allow us to assess the influence of the environment on these high energy objects with unprecedented reliability.