Two Populations Of Carbon-Enhanced Metal-Poor Stars In The Disk System Of The Milky Way

We present a chemodynamical analysis of low-resolution (R similar to 1300) spectroscopy of similar to 50,000 stars from the AAOmega Evolution of Galactic Structure survey, focusing on two key populations of (in total) 650 carbon-enhanced metal-poor (CEMP) stars within the disk system of the Milky Way: a mildly prograde population (L ( z ) < 1000 kpc km s(-1)) and a strongly prograde population (L ( z ) > 1000 kpc km s(-1)). Based on their chemical and kinematic characteristics, and on comparisons with similar populations found in the recent literature, we tentatively associate the former with an ex situ inner-halo population originating from either the Gaia Sausage or Gaia-Enceladus. The latter population is linked to the metal-weak thick disk. We discuss their implications in the context of the formation history of the Milky Way.