UnveilingBlackHoles · Unveiling the population of supermassive black hole binaries near merger

Unveiling the population of supermassive black hole binaries near merger

Supermassive black holes pair together at the centers of newly collided galaxies. If they eventually spiral towards one another and coalesce, they would contribute the strongest sources of gravitational waves in the universe, at frequencies which will be detectable in the near future. However, the steps between galaxy merger and black hole merger are still not understood, and while candidates exist, there is yet no definitive evidence for such supermassive binaries in the late stages of inspiral. This work has made strides towards further understanding this issue by carrying out state-of-the-art numerical hydrodynamical calculations of the interaction of these binaries with gas expected to exist at the centers of binary harbouring galaxies. Results of these calculations have been and will continue to be used to 1) improve theoretical predictions of binary populations and 2) characterise electromagnetic signatures of accreting supermassive black hole binaries with which to find these elusive pairs. Finally understanding this issue would provide further insight into the mutual growth of galaxies and black holes across cosmic time and hence provide a more complete picture of the build up of these entities as we now observe them in our universe. It will also provide necessary theoretical preparation for the coming observations of low frequency gravitational waves with experiments like the Pulsar timing arrays and the Laser Interferometer Space Antenna (LISA).

Data: CORDIS, © European Union