The stellar mass of the Gaia-Sausage/Enceladus accretion remnant

Understand

The \textit{Gaia}-Sausage/Enceladus (GS/E) structure is an accretion remnant which comprises a large fraction of the Milky Way's stellar halo.

• We study GS/E using high-purity samples of kinematically selected stars from APOGEE DR16 and \textit{Gaia}.
• Employing a novel framework to account for kinematic selection biases using distribution functions, we fit density profiles to these GS/E samples and measure their masses.
• We find that GS/E has a shallow density profile in the inner Galaxy, with a break between 15--25~kpc beyond which the profile steepens.