All are cordially invited to a colloquium talk featuring Dr. Francois Foucart, Lawrence Berkeley National Laboratory. Dr. Foucart will present his talk, “Simulating Mergers of Neutron Stars and Black Holes for Multi-messenger Astronomy” on Tuesday, Sept. 15, at 4:10 p.m. in Webster B17.
Meet with our guest speaker and enjoy refreshments before the talk at 3:45-4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract: This fall will see the first scientific run of the Advanced LIGO detector. Within a few years, we expect LIGO to provide direct detections of gravitational waves, most likely from mergers of neutron stars and black holes. In the presence of at least one neutron star, these gravitational waves may be followed by powerful electromagnetic signals. Short gamma-ray bursts are thought to be produced by the remnant of binary mergers. Additionally, r-process nucleosynthesis in neutron-rich material ejected during the merger can power optical or infrared transients days after the merger, and may produce a large fraction of the heavy elements observed today in the solar system (gold, uranium,…). Numerical simulations play a critical role in the study of these systems. Models of the gravitational wave signal are necessary for detection and parameter estimates in LIGO, including for possible measurements of neutron star radii which could help us place new constraints on nuclear physics. The interpretation of most electromagnetic signals also requires an understanding of how they are produced in binary mergers, and of how their properties are related to the binary parameters. In this talk, I will review recent simulations of black hole-neutron star and binary neutron star mergers, and what they tell us about the gravitational wave and electromagnetic signals that we are soon to observe. I will also discuss the importance of the many physical processes which have to be included in order to obtain reliable predictions: general relativity, nuclear-theory based equations of state to describe the neutron star matter, neutrino-matter interactions and magnetic fields.
