Variations in the absorption of X-rays from the eclipsing, highly obscured high-mass X-ray binary IGR J17252-3616
This illustration shows the eclipsing X-ray binary system IGR J17252-3616 in different orbital phases. The system consists of a neutron star that is accreting mass from the stellar wind released by its companion, a blue supergiant star.
IGR J17252-3616 is also a highly obscured high-mass X-ray binary: the neutron star is deeply embedded in the stellar wind, which absorbs part of the radiation from the accretion process – in particular, at soft X-ray energies.
As the two components of the system move around one another and the tail of material trails the neutron star, different amounts of absorbing material may occur along the line of sight to a distant observer. As a result, soft X-ray emission from the system is observed with distinctive variation in its absorption, depending on the orbital phase of the system. This is shown in the graph in the lower part of the illustration.