Institute of research into the fundamental laws of the Universe

X-ray binaries (or microquasars) represent excellent laboratories for testing physical phenomena in the most extreme environments. Composed of a compact star (black hole or neutron star) accreting matter from a companion star, they have been observed for several years at various wavelengths, allowing to characterize a set of complex activities. A very varied physics is thus opened to the modelers.



The goal of this thesis will be to study the activities of binary black holes recently discovered in our Galaxy. The main objective is to understand the connections between accretion and ejection processes, but more particularly to constrain the energy of their relativistic jets from calorimetric measurements made during their interactions with the surrounding medium. The modeling of such interactions brings new constraints on the energy balance of black holes, information that is essential for the understanding of these systems.

The intergalactic magnetic field pervading the cosmic voids is suspected to be a relic field originating from the very first epoch of the cosmic history. The goal of this PhD is to look for signatures of this field in the high-energy data of gamma-ray bursts, and to predict the ability of the future CTA observatory to constrain its properties. This work combines both theoretical modelling and analysis of simulated CTA data.