Black Hole Initiative
Title: Discovery and Opportunity in the X-ray Time Domain
Abstract: Ambitious X-ray observatories have enabled a rapid expansion in our knowledge of the X-ray time domain. With state-of-the-art facilities like Chandra, XMM Newton, and Swift performing surveys over a decade and counting, variability catalogs are increasingly rich. Meanwhile, high time resolution from the likes of NuSTAR and NICER (and RXTE before them) continue to uncover new physics in individual systems. These efforts have lead to the discovery of high-energy EM counterparts to the first binary neutron star merger detected via gravitational waves, a likely pulsar-ULX connection, possible magnetar oscillations, X-ray flares from the closest supermassive black hole, Sgr A*, and enabled reverberation mapping of AGN, to name only a few. I will review a few highlights from the X-ray time domain and briefly describe what we hope to achieve with upcoming and proposed X-ray missions.