The cosmic origin of the rapid neutron capture elements
2020-03-11
12:00
CSIC
Sala Alberto Lobo (ICE building, UAB Campus)
The processes that create the elements that make up the periodic table were laid down theoretically in the late 1950s, but the cosmic forges that actually carry out these processes have been more difficult to identify. The rapid (r) neutron capture process creates half of all the elements heavier than iron and the bulk of the heaviest elements, including almost all gold, platinum, and uranium. Its site is currently a major source of debate.
I present recently uncovered direct spectroscopic evidence for the creation of r-process elements in the merger of two neutron stars, proving that such mergers do create large quantities of heavy elements and that neutron stars are composed of neutron-rich matter, a fact not spectroscopically proven until now. However, the element we find is a light r-process element, not a heavy one, and other lines of evidence suggest there may be a second source of r-process elements in the Universe.