Speaker
Description
Microquasars are Black Hole X-ray binaries that show bright emission at energies above 1 keV along with radio jets. These are transient objects that are typically only visible for a few months during their so-called “eruption”, and go back into quiescence for years or decades. During these eruptions, the Black Hole accretes matter from its stellar companion and the resulting accretion disk is visible in X-ray around 1 keV. Some of those photons are reprocessed by inverse Compton scattering on a hot corona around the BH which is detectable in gamma-ray between 10 and 150 keV. A new high-energy component above 150 keV has been seen in some sources and its precise origin is still unknown: it could come either from Compton scattering on relativistic nonthermalized electrons of the corona, or from the base of the jet. The cumulated data of the INTEGRAL satellite over its 20+ years of observations will help us understand this "hard gamma-tail". The SVOM mission will also be a precious ally for combined observation of the most prominent microquasars (Cyg X-1, GRS1915, etc…).
