Assigned ID: 280 ----- Attempting Submission 1 (Fri Feb 25 04:34:00 GMT 2011) ----- When measuring the stellar velocity dispersion of a spheroid, one is actually measuring a flux-weighted line-of-sight velocity dispersion along a single sight-line during a single epoch in the galaxy's evolution. The effect of dust extinction on this flux-weighted measurement is unclear. Furthermore, it is not always clear whether the galaxy being observed is fully dynamically relaxed. If the galaxy is not in a completely quiescent state--due to a recent interaction--the velocity dispersion may be evolving. It is not known how significantly nor how rapidly the velocity dispersion fluctuates during interactions such as mergers. Knowledge regarding the anisotropy of the velocity dispersion tensor is also lacking for such systems. We propose performing the simulations necessary to properly contextualize observations of dusty and non-quiescent galaxies. This will allow observers to better understand measurements of central stellar velocity dispersion in the spheroidal component of galaxies. Any project in which central stellar velocity dispersion is measured will potentially be affected by this work (e.g. GO-10216 and GO-11208). In the proposed research, we will obtain high time-resolution data regarding the evolution of stellar velocity dispersion during numerical simulations of galaxy mergers. In order to include the effects of dust-extinction, we will measure velocity dispersion using a flux-weighting method that is consistent with the observational technique. For this task, the latest version of the radiative transfer code, Sunrise, will be used to create images and Doppler-broadened spectra of the simulated galaxies.

UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 Medium false 0.0 0.0 false false true false SUPPORTED