Research project Rare explosions from the most massive stars
Massive stars (at least 8 times that of the sun) end their lives in spectacular explosions known as supernovae. Modern large-scale supernova surveys are finding new, rare types of cosmic explosions, expanding our view of both possible stellar deaths and supernova explosion physics.
The ERC-funded project TransPIre seeks to understand the final fates of the very most massive stars, several hundred times the mass of the sun, where stellar evolution theory predicts that a different physical process in the core known as the "pair-instability" should trigger the final explosions. We use data from the ongoing Zwicky Transient Facility as well as the upcoming Vera Rubin Observatory to search for these rare, luminous explosions.
Project description
Two recent revolutions in time-domain astronomy are transforming our understanding of stellar evolution in the most massive regime: the detection of gravitational waves from binary black holes, and the discovery of new and rare classes of supernovae from wide-field transient surveys. With this, a long-standing prediction from stellar evolution theory is gaining new relevance: that stars with He cores above ~35 solar masses will encounter an instability due to pair-production, resulting in either a series of pulsations and corresponding mass ejections, or the complete disruption of the core in a pair-instability supernova. Gravitational wave detectors can search for the resulting gap in the black hole mass distribution, while supernova surveys can constrain the occurrence of the pair-instability phenomenon in the low-redshift universe by searching for the associated transients.
With the upgrade in survey volume by the LSST project at Vera Rubin Observatory, we have an unprecedented opportunity to find and study such rare transients. However, there is a substantial needle-in-the-haystack problem to solve in identifying the relevant candidates from a stream of several million alerts per night. To solve this, we draw on both our experience from searching for superluminous supernovae in the ZTF project, ongoing analysis of the state-of-the-art samples of slow-evolving, luminous transients found in this experiment, and new theoretical predictions.
Project members
Project managers
Ragnhild Lunnan
Assistant Professor
Members
Ragnhild Lunnan
Assistant Professor
Seán Brennan
Post doctor
Anamaria Gkini
PhD
Priscila Jael Pessi
Postdoctor
