DARK MATTER HEATING AND EARLY CORE FORMATION IN DWARF GALAXIES

摘要: We present more results from a fully cosmological ΛCDM simulation of group isolated dwarf galaxies that has been shown to reproduce the observed stellar mass and cold gas content, resolved star formation histories, metallicities dwarfs in Local Volume. Here we investigate energetics timetable cusp-core transformation. As suggested by previous work, supernova-driven outflows remove dark matter (DM) cusps create kiloparsec-size cores all systems having M * > 106 ☉. The "DM core removal efficiency"—dark ejected per unit mass—ranges today few dozen, increases with decreasing host mass. Because form bulk their stars prior redshift 1 amount work required for DM heating scales approximately as , unbinding cusp starts early cored profiles is not energetically onerous previously claimed. particles typically migrate 2-3 radii after absorbing percent energy released supernovae. present-day slopes inner profiles, Γ ≡ dlog M/dlog R 2.5-3, simulated "Bashful" "Doc" are similar those measured luminous Fornax Sculptor spheroidals. None circular velocity profile exceeding 20 km s–1 kpc, implying supernova feedback key solve "too-big-to-fail" problem Milky Way subhalos.