Universe Colloquium: Merging neutron stars as sources for gold and gravitational waves

by Andreas Bauswein (MPA)

Wednesday 8 May 2013, 16:30 → 17:30 Europe/Berlin

Seminar room, basement (Universe)

Colliding neutron stars give rise to a number of potentially observable signals which may provide valuable information on astrophysics, nucleosynthesis and high-density physics. As strong emitters of gravitational radiation, neutron-star mergers are prime targets for the upcoming generation of gravitational-wave detectors. Based on an extensive survey of relativistic hydrodynamical simulations we point out that a measurement implies the exciting possibility to determine the stellar structure of neutron stars and thus to constrain the high-density equation of state, which is only incompletely known. Neutron-rich matter getting gravitationally unbound during the merging provides excellent conditions for the rapid neutron-capture process (r-process) forming heavy elements such as gold, platinum and uranium. While the astrophysical site(s) producing these r-process elements is (are) not yet unambiguously identified, we demonstrate that neutron-star mergers are promising events in this respect. Moreover, the radioactive decay of the products of the r-process heat the outflow and allows it to become potentially observable as source of electromagnetic radiation. We present the features of those electromagnetic counterparts and discuss the potential implications of observations, which may also place constraints on unknown neutron-star properties. The Universe Colloquium is followed by a social gathering with wine and cheese.