Special TAPIR Seminar

Despite their importance for understanding the mutual build-up of supermassive black holes and their host galaxies, and the emission of low frequency gravitational waves, there is yet no definitive evidence for sub-parsec separation supermassive black hole binaries (SBHBs) in galactic nuclei. This is partly because the presently employed methods for identifying such SBHBs rely on indirect evidence that takes many years to accumulate. I will discuss new techniques that could provide the first definitive evidence for SBHBs at sub-pc separations using electromagnetic radiation.