Kilonova: Multimessenger and Multiphysics

In 2017, a multimessenger era started with the first gravitational wave detection from the merger of two neutron stars (GW170817) and the rich electromagnetic follow-up. The most exciting electromagnetic counterpart was the kilonova. This provides an answer to the long-standing question of how and where heavy elements are produced in the universe. The neutron-rich material ejected during the neutron star merger (NSM) undergoes an r-process (rapid neutron capture process) that produces heavy elements and generates energy that is radiated as a kilonova. Therefore, one can use the kilonova as a direct observable of the matter ejected in NSM and learn about the extreme conditions that are reached in these events. This requires combing full general relativity simulations with state-of-the-art microphysics for the high-density equation of state and neutrinos, nucleosynthesis calculations involving extreme and still unknown neutron-rich nuclei, radiation transport models for the kilonova with detailed atomic physics information, and multimessenger observations.

The goal of this interdisciplinary seminar will be to bring together a group of experts from different fields and approaches to understand the microphysics and macrophysics of kilonovae and how to use observations to learn about these exciting multimessenger events. We aim to start and strengthen collaborations between atomic physics and astrophysics (atomic astrophysics) following the successful example of nuclear astrophysics. The time line of the seminar is critical, since new nuclear and atomic physics data from experiments and advanced theoretical models are now becoming available together with improved astrophysical models and larger samples of observations.