Separating the conjoined red clump in the Galactic Bulge: Kinematics and
  Abundances
  We have used the AAOMEGA spectrograph to obtain R $\sim 1500$ spectra of 714
stars that are members of two red clumps in the Plaut Window Galactic bulge
field $(l,b)=0^{\circ},-8^{\circ}$. We discern no difference between the clump
populations based on radial velocities or abundances measured from the Mg$b$
index. The velocity dispersion has a strong trend with Mg$b$-index metallicity,
in the sense of a declining velocity dispersion at higher metallicity. We also
find a strong trend in mean radial velocity with abundance. Our red clump
sample shows distinctly different kinematics for stars with [Fe/H] $<-1$, which
may plausibly be attributable to a minority classical bulge or inner halo
population. The transition between the two groups is smooth. The
chemo-dynamical properties of our sample are reminiscent of those of the Milky
Way globular cluster system. If correct, this argues for no bulge/halo
dichotomy and a relatively rapid star formation history. Large surveys of the
composition and kinematics of the bulge clump and red giant branch are needed
to define further these trends.
