Galaxies in a simulated ΛCDM Universe – I. Cold mode and hot cores

摘要: We study the formation of galaxies in a large volume (50 h −1 Mpc, 2 × 288 3 particles) cosmological simulation, evolved using entropy and energy-conserving smoothed particle hydrodynamics (SPH) code GADGET-2. Most baryonic mass all masses is originally acquired through filamentary ‘cold mode’ accretion gas that was never shock heated to its halo virial temperature, confirming key feature our earlier results obtained with different SPH code. Atmospheres hot, virialized develop haloes above 2–3 10 11 M � , transition nearly constant from z = 0. Cold persists mass, especially at ≥ 2. It dominates growth low-mass times, it main driver cosmic star history. Our suggest cooling shock-heated gas, which has been focus many analytic models galaxy spanning more than three decades, might be relatively minor element formation. At high redshifts, satellite have rates similar central same but < 1t he satellites are well below those comparable galaxies. Relative simulations, GADGET-2 simulations predict much lower ‘hot component. Hot compete cold near only ≤ 1. inefficient