Where do binary black holes come from? How do we find it out?

by Davide Gerosa (California Institute of Technology)

Monday 15 Jan 2018, 14:30 → 16:00 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

Gravitational-wave observations provide a new tool to study formation and evolutionary processes of black holes. I first introduce the main black-hole binaries formation pathways and describe which observables can help us to distinguish between them. I then present some recent attempts to extract astrophysical constraints from the gravitational-wave events of LIGO’s first observing runs. In particular, the spin misalignment of the black-hole binary GW151226 ("the Boxing Day event") can be used to measure the linear momentum imparted to black holes at birth, hence the degree of asymmetry of the related supernova explosions. The first events also provide marginal constraints on the presence of multiple merger generations (i.e. merging black holes which are the results of previous mergers, rather than stellar collapse). I also show how astrophysical priors can be used in the data analysis process to maximize the astrophysical information extracted from these landmark discoveries. The future is bright and loud: as hundreds of gravitational-wave events are expected in the next few years, these elusive gravity messengers will soon prove their immense potential to shape our understanding of the astrophysical world.

Slides Gerosa.pdf