The Baryons in the Milky Way Satellites

Understand

We investigate the formation and evolution of satellite galaxies using smoothed particle hydrodynamics (SPH) simulations of a Milky Way(MW)-like system, focussing on the best resolved examples, analogous to the classical MW satellites.

• Comparing with a pure dark matter simulation, we find that the condensation of baryons has had a relatively minor effect on the structure of the satellites' dark matter halos.
• The stellar mass that forms in each satellite agrees relatively well over three levels of resolution (a factor of ~64 in particle mass) and scales with (sub)halo mass in a similar way in an independent semi-analytical model.
• Our model provides a relatively good match to the average luminosity function of the MW and M31.