Imre Bartos (Columbia)

Prospects for Observing the Encounter of G2 with a stellar-mass BH

Galactic nuclei are expected to be densely populated with stellar and intermediate mass black holes. Exploring this population will have important consequences for the observation prospects of gravitational waves as well as understanding galactic evolution. The gas cloud G2 currently approaching Sgr A* provides an unprecedented opportunity to probe the black hole population of the Galactic nucleus. We examine the possibility of a G2-black hole encounter and its detectability with current X-ray satellites, such as Chandra and NuSTAR. We find that multiple encounters are likely to occur close to the pericenter, which may be detectable upon favorable circumstances. This opportunity provides an additional, important science case for leading X-ray observatories to closely follow G2 on its way to the nucleus.