Was the Milky Way a Quasar?
Summary
This episode explores the discovery of the Fermi Bubbles, massive gamma-ray structures extending from the Milky Way’s center, suggesting our galaxy’s supermassive black hole, Sagittarius A*, experienced a violent active phase just a few million years ago. The host discusses competing theories for their origin, including a supernova starburst or a black hole feeding event, and proposes a combined scenario where AGN activity triggered star formation. Recent radio and X-ray observations indicate the black hole may be becoming active again, highlighting that the Milky Way’s calm is temporary.
Topics discussed
Sponsor reads: LinkedIn and Uber Eats
Introduction: The Milky Way's violent past
Active Galactic Nuclei and Sagittarius A*
Discovery of the Fermi Bubbles
Sponsor reads: LinkedIn and Edward Jones
Gamma-ray physics and bubble detection
Origin theories: Starbursts vs. Black Hole
Sponsor reads: LinkedIn and Edward Jones
Evaluating the AGN jet hypothesis
Combined model: AGN triggering starburst
New radio bubbles and recent activity
Sponsor read: Uber Eats
Future risks and historical visibility
Q&A: Earth's age and radiometric dating
Sponsor reads: Edward Jones, USAA, Uber Eats
Listen ad-free on Castria