How Black Holes Kill Galaxies
Summary
This episode explores the tight correlation between supermassive black holes and their host galaxies, proposing that black hole feedback quenches star formation to limit galactic growth. It details how quasar activity heats or expels gas, creating a self-regulating cycle that explains why massive elliptical galaxies are "red and dead." The segment also addresses listener questions regarding the distribution of neutron star collision products, the definition of radioactive half-lives, and the detectability of strange matter.
Topics discussed
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Introduction to supermassive black holes and their galactic connection
The mystery of the tight correlation between black hole and galaxy mass
Bottom-up hierarchical galaxy formation and black hole growth
Why black holes and galaxies do not grow in perfect lockstep
Red and dead galaxies: The cessation of star formation in ellipticals
Quenching mechanisms: Quasar activity and gas expulsion
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The feedback loop: How black holes limit their own growth
Cosmic history of star formation and its decline over time
Alternative quenching mechanisms and the peak of the quasar epoch
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Q&A: Neutron star collisions and the Fermi Paradox
Q&A: Correction on radioactive half-life definitions
Q&A: The stability and detection of strange matter
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