092004

HD168112 is an eccentric wide O + O binary known for its synchrotron radioemission. The relativistic electrons responsible for this emission areaccelerated by the strong shocks between the stellar winds of both components.These shocks heat the post-shock plasma leading to a strong X-ray emission thatvaries with orbital separation d. We propose to investigate the impact of thepopulation of relativistic electrons on the hydrodynamic shocks and the X-rayemission. For this purpose we propose to collect XMM-Newton observations ofHD168112 during its next periastron passage in March 2023. We will search fordeviations of the X-ray luminosity over the 1/d relation for adiabatic shocksand constrain any hard X-ray tail due to non-thermal X-rays produced via inverse Compton scattering. [truncated! Please see actual data for full text]