Title: Hunting Compact Objects with Gaia

Abstract: Massive stars live fast, die young and leave behind beautiful corpses. These "stellar corpses" could be neutron stars or black holes and are collectively referred to as compact objects. While it is estimated that there over a hundred million compact objects in our galaxy, only a small fraction of them has been discovered. Often detections are only possible under specialised circumstances, such as close proximity to Earth, interaction with a close binary companion or alignment (as in the case of pulsars).

This could change with the Gaia mission. Gaia is a satellite that tracks the positions of roughly a billion stars with unprecedented precision. Among other things, Gaia will be able to detect compact objects in binaries according to the motion of their companion. In this talk I'll present predictions for the number of compact objects Gaia will detect, based on population synthesis, and I'll show how the statistical distributions of the results can be used to constrain currently unknown parameters related to the evolution of massive stars, such as black hole natal kick velocities and the common envelope energy parameter. These parameters are crucial for obtaining accurate estimates of the rates of gravitational wave sources.