A monolithic collapse origin for the thin/thick disc structure of ESO 243-49

Understand

ESO 243-49 is a high-mass (circular velocity $v_{\rm c}\approx200\,{\rm km\,s^{-1}}$) edge-on S0 galaxy in the Abell 2877 cluster at a distance of $\sim95\,{\rm Mpc}$.

• To elucidate the origin of its thick disc, we use MUSE science verification data to study its kinematics and stellar populations.
• The thick disc emits $\sim80\%$ of the light at heights in excess of $3.5^{\prime\prime}$ ($1.6\,{\rm kpc}$).
• The rotation velocities of its stars lag by $30-40\,{\rm km\,s^{-1}}$ compared to those in the thin disc, which is compatible with the asymmetric drift.