The origin of the heaviest elements in our universe—those produced via the rapid neutron capture process ("r-process")—remains a question of intense debate. Although the kilonova emission that accompanied GW170817 revealed neutron star mergers to be an important r-process source, several independent observations hint that mergers may not be the only source, particularly at low metallicity. I will argue that mass-loaded outflows from the accretion disk feeding the newly-formed black hole— responsible for powering the gamma-ray burst (GRB) jet—was the dominant source of r-process elements in GW170817. However, broadly similar accretion flows are created in another explosive transient—the collapse of massive rotating stars ("collapsars") which give rise to GRBs of longer duration, and simple estimates show that the integrated r-process yields of collapsars could compete with those of neutron star mergers over the history of the Galaxy. I will discuss observational tests of whether collapsars produce r-process elements using infrared observations of GRB supernovae, particularly with JWST and the Roman Space Telescope.

Speaker: Brian Metzger (Columbia University and Center for Computational Astrophysics)

All 2023 Spring Colloquium talks are held on Wednesdays at 3:00 PM.  You may join the colloquium in person at STScI’s John N. Bahcall Auditorium or virtually or at the links listed below. 

• Facebook Link: https://www.facebook.com/STScILiveScienceEvents
• Live Captioning Link: https://www.streamtext.net/player?event=STSI-ColloqiumSeries

Please direct questions or comments to contact above. The Spring Colloquium Committee members are: JHU Members: Kevin Schlaufman, Co-Chair, Ethan Vishniac, Arshia Jacob and STScI Members: Joel Green, Co-chair, Armin Rest, Co-chair and Andreea Petric.