Bethe Colloquium

Probing heavy element nucleosynthesis through electromagnetic observations

by Gabriel Martínez-Pinedo (GSI & TU Darmstadt)


Half of the elements heavier than iron are produced by a sequence of
neutron captures, beta-decays and fission known as r-process. It
requires an astrophysical site that ejects material with extreme
neutron rich conditions. Once the r-process ends, the radioactive
decay of the freshly synthesized material is able to power an
electromagnetic transient with a typical intrinsic luminosity. Such
kilonova was observed for the first time following the gravitational
signal GW170817 originating from a merger of two neutron stars. This
observation answered a long lasting question in nuclear astrophysics
related to the astrophysical site of the r-process. In this talk, I
will summarize our current understanding of the r-process and the
answers provided by recent observations. I will also illustrate the
unique opportunities offered by kilonova observations to learn about
the in-situ operation of the r-process and the properties of matter at
extreme conditions. Achieving these objectives, requires to address
fundamental challenges in astrophysical modeling, the physics of
neutron-rich nuclei and high density matter, and the atomic opacities
of r-process elements required for radiative transfer models.