3:30–4:30 pm Maria Goeppert-Mayer Lecture Hall, KPTC 106
Merging neutron stars: source of the rarest and highest energy particles in Nature
Glennys Farrar, NYU
Faculty Host: Henry Frisch
“r-process” nuclei such as Krypton, Gold, Platinum — which require assembly through rapid neutron capture -- primarily originate in binary neutron star mergers (BNSMs). We know this in large part thanks to observations of the gravitational wave event GW170817 and its electromagnetic counterparts, and simulations of them. Recently, several lines of evidence have converged to point to BNSMs as being the source of the highest energy particles in the Universe, called ultra-high energy cosmic rays. These are nuclei with energies more than 10 million times what is achievable with CERN’s Large Hadron Collider; one hits the Earth about once per square kilometer, per century. This colloquium will tell the remarkable story of how it has been possible to identify what UHECRs are, outline the evidence that they are produced in BNSMs, and discuss the broader implications for astrophysics.