Department of Physics and Astronomy
Stony Brook University
7:30 pm; ESS Building, Room 001
Friday, November 02, 2018

More Results from the Neutron Star Merger GW170817

Prof. Jim Lattimer

On Aug. 8, 2017, the first binary neutron star merger was observed, by the gravitational wave detectors operated by LIGO in Washington and Louisiana states and VIRGO in Italy. The initial detection indicated the event was the merger of two nearly 1.4 solar mass neutron stars. This merger was closely followed, in 1.7 seconds, by a short gamma-ray burst which have long been thought to be produced by neutron star mergers. In addition, as soon as the location could be observed with optical telescopes, nine hours post-merger, a luminous glow from expanding matter ejected from the merger was visible. This radiation lasted several weeks, moving largely from optical to infrared emission, suggesting the expulsion of very heavy elements. All in all, the observations seem to confirm a prediction from the mid-1970s that decompressing neutron star matter from mergers are the source of about half of the elements heavier than iron in the universe, solving a long-standing mystery of their origin. Since this event, scientists have been analyzing the observed gravitational waves for clues concerning the properties of the merging stars. In this talk, I will discuss the latest results and their implications for the high-density equation of state and the internal composition of neutron stars.

Jim Lattimer has been at Stony Brook from 1979 and has focused on nuclear astrophysics. He has taught on many subjects, most frequently on the search for intelligent life in the universe which emphasizes the role of science fact in evolution and climate research.