Measuring properties of accreting black holes with X-ray reverberation

Black holes are the most extreme objects in the universe. They form through an unstoppable collapse of matter by its own gravity. The result is an astrophysical object so compact that the surrounding space-time is bent, modifying the trajectory of the light, to the point that the light itself can be trapped. This makes it difficult to study the characteristics of these objects simply because we are not able to see them. However, the strong gravitational force attracts matter that falls into black holes and before disappearing it emits light. This thesis studies the radiation emitted by this luminous matter around black holes. In particular it analyses spectral properties and the time variability of this radiation and combining these two aspects infers characteristics of the black holes such as their mass.