Heavy Element Abundance Dispersion in Globular Clusters

Dr. Evan Kirby and graduate student Pranav Nalamwar seek an undergraduate student to assist in an astrophysics project on globular cluster spectroscopy. We are interested in how the universe's heaviest elements, from the neodymium in magnets to the gold in earrings, are formed. The astrophysical sites currently theorized to produce these rapid neutron capture process (r-process) elements include magneto-rotational supernovae, neutron star mergers, and collapsars. However, further observations and theoretical models are needed to properly constrain which site produces r-process elements in different locations like dwarf galaxies and globular clusters. To tackle this problem, we used the HIRES spectrograph on the Keck observatory to take high-resolution spectra (see figure from Kirby et al. 2023 for an example) of red giant branch stars in the globular clusters M2 and M5. By analyzing their spectra via tools such as Spectroscopy Made HardeR (SMHR), the student will identify elements like Europium and Neodymium to compute their abundances. Dispersion in r-process abundances within these stars can help constrain the astrophysical origin of the r-process, an unsolved problem despite the observation of coalescing neutron stars (GW170817) producing r-process elements.