Speaker
Description
Recent mass models of massive early-type galaxies (ETGs) have revealed compact, central mass-to-light (M/L) gradients, potentially indicating variations in the stellar populations and/or initial stellar mass function. These gradients may be linked to in-situ and ex-situ stellar components, as supported by the two-phase formation scenario. Such multiple-component systems challenge "classical" dynamical modelling techniques that assume a single stellar population. We have developed a new multi-component Schwarzschild orbit-superposition dynamical code to study the superposition of distinct stellar populations.
Our new framework is designed to simultaneously fit the observed luminosity density and distinct kinematics (LOSVDs) of multiple stellar subcomponents derived via the non-parametric spectral decomposition code WINGFIT. Having successfully validated the framework's capability to recover intrinsic properties, such as mass gradients and kinematics, using mock N-body simulations, we present how this framework performs on real IFU data. The goal of this analysis is to dynamically disentangle the galaxy's different stellar subpopulations to measure improved stellar M/L ratios. This approach provides a direct test of whether stellar population variations can explain the observed M/L gradients or if additional physical processes are required.