May 08, 2014
Rosemary Wyse, The John Hopkins University
"The Disks of the Milky Way Galaxy"
I will discuss our current understanding of the disk(s) of the Milky Way. The vertical structure of stellar disks is determined by the relative importances of diverse physical processes, including gaseous dissipation prior to star formation, subsequent gas accretion into the disk, heating mechanisms such as interactions with transient spirals, and the mass ratios and gas content of merging systems. The radial structure reflects star-formation rates, angular momentum (re)distribution and interactions within the disk. The kinematic, chemical and age distributions of the stellar populations of present-day disks, as a function of scale-height and scale-length, provide further constraints on disk evolution. Decomposition of disks into distinct spatial components -- such as thin and thick -- is most meaningful when the spatial decomposition is accompanied by distinct
stellar populations and/or different physical processes determining their properties. The most detailed information is available for stars in the Milky Way galaxy and I will demonstrate this decomposition based on recent results for the Milky Way disks.