The X-Ray Binary Population with Fermi-LAT

Abstract

Binary star systems represent a significant proportion of the Galactic stellar population, with X-ray binaries being an important subset of these for high energy astrophysics. Although hundreds of X-ray binaries are detected in the Milky Way and beyond, only 12 of these systems are listed in the 4FGL-DR2, the latest Fermi-LAT point source catalogue. With such a small number detectable by Fermi-LAT, much is still unknown about the mechanisms by which these systems emit -rays. We present the method and current status of our large-scale survey of the X-ray binary population using over 12 years of Fermi-LAT data, and current catalogues and background models.

Modelling the expected very high energy γ-ray emission from accreting neutron stars in X-ray binaries

“…In this regard, we performed simulations assuming L x = 3 × 10 36 erg s −1 , for strong and weak shielding for the gap, and B = 10 9 G and B = 10 10 G which did not produce any emission of γ−ray photons able to escape from the accretion disc. Harvey et al (2022a) pointed out that, although the population of LMXBs in our Galaxy is almost twice than that of HMXBs, its members are only half as many in the latest . γ-ray luminosities with respect to the input X-ray luminosity for different magnetic field strengths, strong and weak shielding, and for photons escaped from the disc (dashed lines) and photons that reached the observer (solid lines).…”