University of California, Davis
Physics Department
Cosmology Seminar
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The UV radiation produced by massive stars in the dense ISM of starburst
galaxies is absorbed, scattered, and reprocessed into the IR by dust grains. I
consider the structure of marginally Toomre-stable
starburst disks under the assumption that the associated radiation pressure
provides the dominant vertical support against gravity. This assumption is
particularly appropriate when the disk is optically thick to its own infrared
radiation, as in the central regions of Ultraluminous
Infrared Galaxies (ULIRGs). I will discuss the
implications of this important feedback process. In particular, because the
disk radiates at its Eddington limit the Schmidt-law for star formation changes
qualitatively in the optically-thick limit. I extend the model from
many-hundred parsec scales to sub-parsec scales and address the problem of AGN
fueling. I will show that a strong bifurcation exists between models whose
spectra are starburst dominated and those that are AGN dominated. The latter
models contain a compact starburst on 1-10 parsec scales. I speculate on the
nuclear obscuration of some bright AGN and the origin of the disk of young
stars in the galactic center.
12:10 pm, 416 Phy/Geo