The universe’s biggest galaxies have both vast atmospheres and supermassive central black holes. Coupling between those two components of a large galaxy couple regulates the galaxy’s star formation rate. Models of interactions between a supermassive black hole and the large-scale atmosphere suggest that the energy released as cold gas clouds accrete onto the black hole suspends the atmosphere in a state that is marginally stable to formation of cold clouds.
A growing body of observational evidence indicates that many massive galaxies, ranging from the huge central galaxies of galaxy clusters down to our own Milky Way, are close to that marginal state. The gas supply for star formation within a galaxy in such a marginal state is closely tied to the galaxy's central potential well, as traced by the central velocity dispersion of its stars. Those findings suggest that energy released during black-hole accretion shuts down star formation when the central potential well depth exceeds a critical value determined by the galaxy’s supernova heating rate.
Bio:
I’m currently an astronomy professor at Michigan State University. My journey here started in suburban Philadelphia. I graduated from Cheltenham High School in 1979 and from Princeton in 1983, with an A.B. in Astrophysical Sciences. My Ph.D. in Astrophysics (1990) is from the University of Colorado. Then came three years as a Research Fellow at Caltech, two more as a Hubble Fellow at Johns Hopkins, and eight as an astronomer at the Space Telescope Science Institute, working on the Hubble Space Telescope project, before Michigan State brought me on board in 2003.
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2023-03-06T15:00:002023-03-06T16:00:00Baryon Cycles in the Biggest GalaxiesEvent Information:
Abstract:
The universe’s biggest galaxies have both vast atmospheres and supermassive central black holes. Coupling between those two components of a large galaxy couple regulates the galaxy’s star formation rate. Models of interactions between a supermassive black hole and the large-scale atmosphere suggest that the energy released as cold gas clouds accrete onto the black hole suspends the atmosphere in a state that is marginally stable to formation of cold clouds.
A growing body of observational evidence indicates that many massive galaxies, ranging from the huge central galaxies of galaxy clusters down to our own Milky Way, are close to that marginal state. The gas supply for star formation within a galaxy in such a marginal state is closely tied to the galaxy's central potential well, as traced by the central velocity dispersion of its stars. Those findings suggest that energy released during black-hole accretion shuts down star formation when the central potential well depth exceeds a critical value determined by the galaxy’s supernova heating rate.
Bio:
I’m currently an astronomy professor at Michigan State University. My journey here started in suburban Philadelphia. I graduated from Cheltenham High School in 1979 and from Princeton in 1983, with an A.B. in Astrophysical Sciences. My Ph.D. in Astrophysics (1990) is from the University of Colorado. Then came three years as a Research Fellow at Caltech, two more as a Hubble Fellow at Johns Hopkins, and eight as an astronomer at the Space Telescope Science Institute, working on the Hubble Space Telescope project, before Michigan State brought me on board in 2003.
Learn more:
View Dr. Voit's personal website here.
View Dr. Voit's Michigan State faculty webpage here.
Event Location:
HENN 318
