WoU-MMA: Multiple Approaches to Multi-Messenger Astronomy

GW170817 was the name given by astronomers to the merger of two neutron stars witnessed through its gravitational wave siren, an associated gamma-ray burst, and its glow at all wavelengths of light, marking the beginning of a golden age in time-domain multi-messenger astronomy. Through this discovery, our knowledge of gravity, nuclear physics, the origin of the heaviest elements, and cosmology were all dramatically expanded. A research team at the University of California at Santa Cruz (UCSC), which was instrumental in the discovery of GW170817, will lead an international program to research electromagnetic (EM) counterparts to gravitational wave (GW) events. The overriding questions addressed by this proposal are: What are the EM counterparts to GW events? What are the demographics of the mergers of compact astrophysical objects like neutron stars and black holes? What environments produce an enhanced rate of neutron-star mergers? What elements are generated and expelled by these events? How can astronomers best use all GW and EM data with advanced theoretical models to improve the answers to these questions and more? This project will support two UCSC graduate students, one in observational work from telescopes, and the other in theoretical modeling and numerical simulations. The program will also work to increase participation of members of historically marginalized groups in astrophysics, cross-fertilize the training of scientists and students in the visual arts and digital media, and engage dozens of high school students directly in our research. The main scientific goals are to (1) discover and characterize new electromagnetic (EM) counterparts to gravitational wave (GW) events, (2) produce new theoretical models that follow the merger process from hydrodynamics of the initial event to EM emission, (3) study the demographics of compact-object mergers, and (4) combine data and theory to understand the physics of r-process nucleosynthesis. By the end of this project, the investigators expect to increase the number of EM counterparts of GW events from one to potentially more than ten. They will characterize individual events and the larger population of compact-object mergers. They will improve theoretical models, iteratively improving models and data and use the data, models, and advanced statistical techniques to measure the local cosmic expansion rate. This award advances the goals of the Windows on the Universe Big Idea. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.