Separating the conjoined red clump in the Galactic Bulge: Kinematics and Abundances

Understand

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.