COLLOQUIUM Philipp Podsiadlowski, Oxford University

How Stars end their Lives

While the basic evolution of stars has been understood for many
decades, there are still major uncertainties in our theoretical
understanding of how stars end their lives, both in the context of
low- and intermediate-mass stars (including the Sun) and massive
stars. After reviewing some of key principles that govern the
structure and evolution of stars, I will present recent progress that
has been made for both groups of stars. I will argue and present
numerical simulations that show that all stars become dynamically
unstable when they become very large giants, which leads to sporadic,
dynamical mass ejections. Low- and intermediate-mass stars may lose
all of their envelopes as a consequence, leaving white-dwarf
remnants. More massive stars experience core collapse, leaving a
neutron-star or black-hole remnant, possibly associated with a
supernova explosion. I will show how the dramatic recent progress on
understanding the core-collapse process, for the first time, allows us
to connect the late evolution of massive stars with the resulting
supernova explosions and the final remnants. One prediction is that
their is a characteristic distribution of black-hole masses which can
be tested with LIGO. Indeed, there is already some supporting evidence
in the O3 science data, and the data of the O4a science run, expected
to be published this August, should allow a quantitative assessment
of these predictions.

Talk in presence and via Zoom:

https://uni-hamburg.zoom.us/j/66006535328?pwd=aGkrSjJIYmZjK0VpYlpGL0ZrdHg2UT09