Astronomy & Astrophysics Seminar: The Cosmic Dances of Massive Stars
Tomer Shenar, University of Amsterdam
Massive stars might be rare, but their imprints across many astrophysical disciplines are inescapable. They enrich the Universe with heavy elements and ionize their host galaxies. They produce some of the most powerful explosions known: supernovae and gamma-ray bursts. Upon death, they collapse into neutron stars and black holes, which we now observe merging in the high-redshift Universe via gravitational-wave emission. The observed rate of such merging events is expected to grow by orders of magnitudes in the coming years, placing massive-star research at the core of modern astrophysics. A major complexity in our understanding of massive stars is their tendency to interact with companion stars throughout their lives. Such massive-star interactions often lead to the stripping, rejuvenation, or even merging of massive stars, impacting stellar populations across all masses and galaxies. In my talk, we will journey across the evolutionary path of a prototypical massive binary, from birth to death. I will focus on observed populations of stars that represent the pre-interaction, post-interaction, and final core-collapse phases: OB-type binaries, Wolf-Rayet stars and Be stars, and black holes. I will present recent advances in our understanding of these populations, including the discovery of a new population of stellar-mass black holes. Finally, I will highlight open problems in the field which I aim to tackle in my proposed research at TAU, involving ongoing and upcoming spectroscopic surveys and the development of new tools for the spectroscopy of massive binaries and supernovae.
Seminar Organizer: Dr. Iair Arcavi