Binary-Stripped Stars: from Atomic Scales to Cosmic Dawn
DIPC Seminars
- Speaker
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Ylva Gotberg
Institute of Science and Technology Austria (ISTA) - When
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2025/11/11
14:00 - Place
- DIPC Josebe Olarra Seminar Room
- Host
- Nate Bastian
- Add to calendar
-
iCal
A third of all massive stars are expected to lose their hydrogen-rich envelopes through interaction with a binary companion, leaving the hot and compact helium core exposed. Such "stripped stars" are predicted to be the main progenitors of hydrogen-poor core collapse supernovae (type Ibc), to constitute two necessary steps for the creation of binary neutron stars that merge in gravitational wave events, and to emit so much ionizing radiation that they contributed to cosmic reionization. Despite their importance, stripped stars remained elusive until recently, when we observed a first set in the Magellanic Clouds. The discovery of stripped stars means that theoretical models that previously had few to no observational benchmarks now face reality. Our first comparisons show, for example, that classical models of binary mass transfer lose too much angular momentum and that stripped star winds are orders of magnitudes weaker than what is typically assumed in binary evolution models. These results directly affect supernova types and rates, and the production of helium-ionizing photons in galaxies. However, to test the evolution of entire stellar populations, it is essential to increase the sample size. I have therefore developed a spectral binary population synthesis code that is targeted for stripped star searches, and prepared the upcoming UV satellite UVEX to excel in stripped star discovery.