University
of California, Davis
Physics
Department
Cosmology
Seminar
"On the Maximum Luminosity of Galaxies and Their
Central Black
I describe the physics of large-scale galactic winds driven by momentum deposition. Momentum injection is provided several sources, most notably radiation pressure produced by the continuum absorption and scattering of UV photons on dust grains. UV radiation can be produced by a starburst or AGN activity (or both). I argue that momentum-driven winds are an efficient mechanism for feedback during the formation of galaxies. I show that there is a limiting, Eddington-like, luminosity, above which star formation or AGN activity can expel a significant fraction of the gas in a galaxy. I argue that elliptical galaxies and their central black holes reach this limit during their formation at high redshift and that this can explain some of the observed regularities of early type galaxies, in particular the Faber-Jackson and M-sigma relations.
Thursday,
June 10, 2004
12:10 p.m., 416 PHY/GEO