On March 13, 2024 CIERA graduate student Anya Nugent was featured on the American Astronomical Society (AAS) Journal Author Series to discuss a recent paper on short gamma-ray bursts (GRBs). Nugent is a member of CIERA Prof Wen-fai Fong‘s group.
Anya Nugent
“This paper focuses on a subset of unique host galaxy environments of short gamma-ray bursts (GRBs),” describes Nugent. “Short GRBs are some of the most luminous and energetic astrophysical explosions and are derived from the merger of two dead, compact objects called neutron stars. Neutron star mergers are also known producers of many heavy, precious elements (like gold and platinum!), so by studying short GRBs and their host galaxies, we can understand how environments, like Earth and the Milky Way, are enriched with these heavy elements.”
“However, neutron star mergers may not be the only producer of these elements (although we lack observational confirmation of any other possible astrophysical source). A current conundrum with a neutron star merger explanation for all of these heavy elements is that they may not be able to merge fast enough to produce the enrichment observed in some very old stars in the Milky Way that formed and were enriched early in the Universe’s history. And, until this paper, there was really no observational evidence that short GRBs occurred in environmental analogs to these old stars.”
“Our paper focuses on using novel techniques to study the environmental properties of 11 of the faintest host galaxies of short gamma-ray bursts (GRBs). These galaxies’ properties are hard to characterize using more ‘normal’ methods because they are so faint and have such limited observational data. We discovered that all of these short GRBs occurred in central locations within low-mass, dwarf galaxies. Dwarf galaxies are incredibly unique as they are representative of environments in the early Universe, thus by finding short GRBs within these environments, we are also proving that some short GRBs are occurring on rapid enough timescales to enrich younger, early Universe environments. The fact that these short GRBs are centrally located (and around a lot more stars), rather than being found in the outskirts of their host stars, also means that the stars around them were likely enriched with heavy elements they produced.”
“So, through this study, we have found the first observational evidence that neutron star mergers could be responsible for the majority of heavy elements in our Universe, even in environments where we didn’t originally expect them to occur!” – Anya Nugent
Hosted by Dr. Frank Timmes, the AAS Journal Author Series presents casual interviews with authors of impactful articles published in the AAS Journal family. The goal of this series is to provide the human story behind the articles for the benefit of other active researchers.
“This was a really cool opportunity to be able to share my work to a broad astronomy audience,” said Nugent, describing the interview process. “I think this author series is important for all of us in the field to pay attention to as we can get detailed insight from the author on their work and paper, adding to the multitude of ways we can learn about and interact with science.”