Finding super-massive black hole binaries from variability – Jorge Cuadra

Super-massive black holes binaries are expected to be common in the Universe. They are unique probes of the hierarchical growth of galaxies. These binaries and their mergers are the loudest sources of gravitational waves, which should be detected in the future with space-born interferometers and pulsar timing arrays. In the meantime, we can use electromagnetic radiation to identify their unusual signatures. In this talk, I will concentrate on two recently found binary candidates: AT 2021hdr, a likely binary caught disrupting a gaseous cloud, and “Ansky”, possibly an extreme-mass ratio binary producing quasi-periodic eruptions. I will discuss how we used variability surveys to find those candidates, their follow-up, and our efforts to model them.