Institute for Advanced Study Astrophysics Seminar

The lecture will present new techniques that will be employed over the coming decade to probe strong field gravity in the vicinity of black holes. Advances in technology (in the form of long baseline interferometry at a wavelength of ~1 millimeter) allow us already to image the silhouette of the black holes in the Galactic center (SgrA*) and M87. I will present the current preliminary data and its implications. Second, the gravitational radiation emitted by tight black hole binaries will be detectable with upcoming observatories, such as Advanced-LIGO and LISA. Third, the recoil induced by the anisotropic emission of gravitational waves in the final plunge of supermassive binaries could produce transient electromagnetic counterparts and also imprint detectable scars on their host galaxies. New surveys for transients (PTF, Pan-STARRS, LSST, WFIRST) will be sensitive to such counterparts, as well as to flares associated with the tidal disruption of stars which get close to the horizon of massive black holes.