Rocking Out to Heavy Metals: Improving Radiative Transfer Modeling of R-Process Transients
The iodine mixed in with table salt, the metals in a car engine, the uranium that powered nuclear power plants, and the gold in a wedding ring: what do they all have in common? These are all elements created via rapid neutron capture, or r-process. Astronomers witnessed the creation of r-process elements for the first time in 2017 with the multi-messenger detection of a binary neutron star merger in both EM radiation and gravitational waves. The emission, powered by the radioactive decay of the freshly synthesized r-process elements, is known as a kilonova. Encoded in the radiation of kilonovae is information that can help answer fundamental astrophysical questions such as what is the equation of state of neutron stars, how much do binary neutron star mergers contribute to the r-process enrichment of the universe, and what is the final fate of the merger remnant. Thus, accurate modeling of their light curves is critical to extracting the answers to these fundamental questions, which in turn requires more complicated models. I will discuss the improvements I made to the radiative transfer code Sedona to better model r-process transients and make progress towards solving these long-standing mysteries. Specifically, I will focus on my work to estimate systematic modeling uncertainties of kilonova parameter fitting, to include non-thermal effects that alter the light curve and better agree with current data, and predicting UV signals from free neutron decay for upcoming missions like UVEX and ULTRASAT.
