Astronomy Seminar

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Date/Time:Friday, 26 Sep 2014 at 4:10 pm
Location:3 Physics
Contact:Steve Kawaler, Physics and Astronomy
Phone:515-294-5440
Channel:Astronomy
Actions:Download iCal/vCal | Email Reminder
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The Formation and Preservation of Exponential Galaxy Disks (Dr. Curt Struck, Iowa State University)

Simple numerical models show the effects of scattering of stars by massive density disturbances in disks, especially massive clumps found in young disks. Regardless of initial density profile, halo potential structure, and the details of the scattering structures, we find a strong tendency to form exponential surface density profiles. On the other hand, there are important differences in how the density profiles evolve and the stellar orbital kinematics, which do depend on halo potential structure and details of the scattering process. Analytic calculations show that external accretion onto evolving disks, at a rate comparable to the disk star formation rate can preserve the exponential profile form. Simple few-body (i.e., halo potential plus softened point-mass clumps) models, with test particle stars, and approximate analytic calculations, provide an important bridge between comprehensive disk evolution simulations and fundamental theory.