Dark Matter Heating and Early Core Formation in Dwarf Galaxies

Understand

We present more results from a fully cosmological LCDM simulation of a group of isolated dwarf galaxies that has been shown to reproduce the observed stellar mass and cold gas content, resolved star formation histories, and metallicities of dwarfs in the Local Volume.

• Here we investigate the energetics and timetable of the cusp-core transformation.
• As suggested by previous work, supernova-driven gas outflows remove dark matter (DM) cusps and create kpc-size cores in all systems having a stellar mass above 1e6 Msun.
• The "DM core mass removal efficiency" -- dark mass ejected per unit stellar mass -- ranges today from a few to a dozen, and increases with decreasing host mass.