This image shows an artist's impression of a highly obscured high-mass X-ray binary, consisting 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 and as a result had eluded searches in this portion of the electromagnetic spectrum. They were discovered in 2003 via hard X-ray observations with INTEGRAL. Astronomers believe that the soft X-rays are absorbed by the wind released by the companion star, which embeds the neutron star.
Illustration credit: ESA/AOES Medialab
Note: For more information, see High Mass X-Ray Binaries Trace the Milky Way's Spiral Arms.