Neutron Star Mergers and the Subtle Light from Heavy Elements

Colloquium: Astronomy Colloquia | May 2 | 4-5 p.m. | 1 LeConte Hall

Speaker/Performer: Dan Kasen, Berkeley

Sponsor: Department of Astronomy

During, or immediately following, the violent merger of two neutron stars, some small fraction of mass may be expelled from the system. If sufficiently neutron rich, this material can assemble into heavy nuclei by rapid neutron capture (the r-process), thereby enriching the Universe with precious metals and rare earth elements. The subsequent radioactive decay of these r-process nuclei should power an electromagnetic glow similar to, but significantly dimmer than, an ordinary supernova. Astronomical surveys may be able to detect such transients in the near future; if they do, we will have uncovered remarkable evidence directly addressing the unknown site(s) of the r-process. Assuming that the advanced LIGO/VIRGO experiments succeed in detecting gravitational waves from neutron star mergers, the radioactive transients may also be our most promising electromagnetic counterparts. I will discuss models of r-process production in neutron star mergers, and present radiative transfer simulations which are telling astronomers how we can look for them.

Event Contact: rhelgens@astro.berkeley.edu, 510-642-5275