DARK MATTER HALOS IN THE STANDARD COSMOLOGICAL MODEL: RESULTS FROM THE BOLSHOI SIMULATION

摘要: Lambda Cold Dark Matter (?CDM) is now the standard theory of structure formation in universe. We present first results from new Bolshoi dissipationless cosmological ?CDM simulation that uses parameters favored by current observations. The was run a volume 250 h ?1?Mpc on side using ~8 billion particles with mass and force resolution adequate to follow subhalos down completeness limit V circ = 50?km?s?1 maximum circular velocity. Using merger trees derived analysis 180 stored time steps we find velocities satellites before they fall into their host halos. excellent statistics halos (~10 million at every moment ~50 over whole history) accurate approximations for such as halo function, concentrations distinct subhalos, abundance function velocity, spatial distribution subhalos. high redshifts concentration falls minimum value about 4.0 then rises higher values mass?a result. velocity functions redshift. while Sheth-Tormen (ST) approximation found spherical overdensity quite low redshifts, ST formula overpredicts nearly an order magnitude z 10. number scales 1/2 host, have same radial dark matter radii 0.3-2 times virial radius. subhalo N(> sub) ?3 circ. Combining Via Lactea-II simulations, inside radius (V sub/58 km s?1)?3 satellite range 4 s?1 < sub 150 s?1.