15) Mass modeling of GCS in external galaxies and lessons from the Milky Way

Abstract: There are several open questions in the field of galaxy formation such as: What is the fraction of accreted stellar mass? What kinds of mergers (major, or minor, gas-rich, or poor ) dominate the formation channels of spiral, elliptical, and lenticular galaxies? What is the mass within the virial radius of the halo? These questions can be addressed through dynamical and chemo-dynamical studies of globular cluster systems (GCS), discrete tracers of the galactic potential and evolution. Dynamical modeling of external galaxies relies on various assumptions in the spatial distribution and kinematic properties of the tracer population in order to project 6D phase space model prediction to 3D observed quantities. To date, the Milky Way is the only galaxy where intrinsic galactocentric positions and velocities of globular clusters can be measured. I will present ongoing work in constraining the enclosed mass of early-type galaxies using their GCS from the Fornax 3D survey. Thereby, paving the way to combine halo mass measurements from the inner regions, with the measurements closer to the virial radius of the galaxy. I will also highlight how dynamical modelling of the Galactic GCS can help us understand potential biases in mass modeling of external galaxies.