Physics Research Conference

The era of advanced gravitational wave (GW) interferometers has just begun. Hearing neutron star mergers may soon even be routine. Seeing the electromagnetic (EM) counterparts would enable measurement of basic astrophysical properties such as the luminosity, energetics, redshift and host galaxy environment of strong-field gravity events. Furthermore, it would serve as a litmus test for whether or not these mergers are indeed the long sought site of r-process nucleosynthesis (and produce half the elements heavier than iron). However, the challenge is unambiguously identifying the predicted faint, fast and possibly red counterpart in the coarse GW localizations. I present an ongoing Caltech EM-GW search motivated by end-to-end simulations. I also present the rapidly growing inventory of optical and infrared transients in the local universe that are fainter, faster and rarer than supernovae. New classes of transients have bridged the luminosity gap between novae and supernovae and represent missing pieces in our understanding of the fate of massive stars and the evolution of compact binaries. The next frontier in gap transients is the discovery of an EM-GW merger. The surge of EM-GW excitement may literally be dubbed the 21st century gold rush.