Artist's impression of a highly obscured high-mass X-ray binary
The image shows an artist's impression of the highly obscured high-mass X-ray binary IGR J17252-3616, which consists of a neutron star that is accreting mass from its companion, a blue supergiant star.
Highly obscured high-mass X-ray binaries exhibit very faint emission at soft X-ray energies: as a result had eluded all searches in this portion of the electromagnetic spectrum. They were discovered via hard X-ray observations with INTEGRAL in 2003. Astronomers believe that the soft X-rays are absorbed by the wind released by the companion star, which embeds the neutron star.
Observations of this source with ESA's INTEGRAL and XMM-Newton space observatories, together with the results from numerical simulations, suggest that the stellar wind is being deflected by the neutron star's gravity. In particular, the mass of the neutron star plays an important role in shaping the variations that are obseved in the absorption of the soft X-ray emission. More massive neutron stars induce a more pronounced deflection on the flow of accreted matter. This results into a thicker and denser tail that trails the neutron star, causing stronger absorption.