Set of Spherical Kilonovae Models with Entropy Parameter

Kilonovae are the electromagnetic transients created by the radioactive decay of heavy elements synthesized in the ejecta from neutron star mergers (NSM). NSMs are thought to be the main source of half of the heavy elements in the universe. These elements are a result of rapid neutron capture (r-process) nucleosynthesis, a process that varies significantly due to local conditions. By better understanding how the local conditions in nucleosynthesis affect kilonovae, we can recover the quantities, like densities and temperatures, at which heavy elements (Au, U, Pu) are synthesized. Since the first kilonova discovery in 2017, much effort has been spent to create models that accurately represent observations. Previous models, however, do not include entropy as a parameter, though entropy is an essential aspect of r-process calculations. In order to solve such a complex problem, we used spherically symmetric models to allow greater variation in parameters. We modeled a grid that accurately accounts for the evolution of entropy as it interacts with other parameters outside of nuclear statistical equilibrium (NSE). These results expand on our current understanding of r-process nucleosynthesis.