Kinematics of Stellar Populations in Post-Starburst Galaxies
  Post-starburst galaxies host a population of early-type stars (A or F), but
simultaneously lack indicators of ongoing star formation such as OII emission.
Two distinct stellar populations have been identified in these systems: a young
post-starburst population superimposed on an older host population. We present
a study of nine post-starburst galaxies with the following objectives: 1) to
investigate if and how kinematical differences between the young and old
populations of stars can be measured; and 2) to gain insight into the formation
mechanism of the young population in these systems. We fit high signal-to-noise
spectra with two independent populations in distinct spectral regions: the
Balmer region, the MgIb region, and the Ca Triplet when available. We show that
the kinematics of the two populations largely track one another if measured in
the Balmer region with high signal-to-noise data. Results from examining the
Faber-Jackson relation and the Fundamental Plane indicate these objects are not
kinematically disturbed relative to more evolved spheroids. A case-study of the
internal kinematics of one object in our sample shows it to be
pressure-supported and not rotationally-dominated. Overall our results are
consistent with merger-induced starburst scenarios where the young population
is observed during the later stages of the merger.
