Ponente
Descripción
We use the Mochima suite of cosmological zoom-in simulations (arXiv:2004.06008) to examine how different star formation and feedback models shape the dark matter distribution in a Milky Way–mass galaxy and its satellites (arXiv:2301.06189). All runs share identical initial conditions, allowing controlled comparisons across subgrid prescriptions. In every hydrodynamical case, the host halo develops a steeper inner dark matter profile than the dark matter–only control, with inner slopes ranging from γ∼1.3−1.8 depending on early stellar bulge mass and feedback strength. Despite bursty star formation in some runs, no fully cored profiles emerge, underscoring the tension between contraction and feedback. The solar neighborhood phase-space distribution of dark matter is also modified: although broadly consistent with standard expectations, the speed distribution at the solar circle shifts due to baryonic contraction.
Satellite survival correlates with host halo concentration and stellar content. Simulations with extended discs and deep central potentials show enhanced tidal disruption of low-mass subhalos, while subhalos with significant stellar mass exhibit greater resilience. The resulting spread in subhalo inner slopes matches the observed cusp–core diversity and is tied to star formation history. These results emphasize the importance of baryonic physics in dark matter modeling, with implications for structure formation, (in)direct detection, and the interpretation of future surveys.
