We investigate the properties and clustering of halos, galaxies and blackholes to z = 0 in the high resolution hydrodynamical simulation MassiveBlack-II (MBII). MBII evolves a ΛCDM cosmology in a cubical comoving volume of V box = (100Mpc/h) 3 and is able to resolve halos of mass M halo = 10 9 M /h. It is the highest resolution simulation of this size which includes a self-consistent model for star formation, black hole accretion and associated feedback. We provide a simulation browser web application which enables interactive search and tagging of halos, subhalos and their properties and publicly release our galaxy catalogs to the scientific community. Our analysis of the halo mass function in MBII reveals that baryons have strong effects, with changes in the halo abundance of 20-35% below the knee of the mass function (M halo 10 13.2 M /h at z = 0) when compared to fits based on dark matter only simulations. We provide a fitting function for the halo mass function valid for the full range of halo masses in MBII out to redshift z = 11 and discuss how the onset of nonuniversal behavior in the mass function limits the accuracy of our fit. We examine the halo occupation distribution of satellite galaxies and present results valid over 5 orders of magnitude in host halo mass. We study the clustering of galaxies, and in particular the evolution and scale dependence of stochasticity and bias. Comparison with observational data for these quantities for samples with different stellar mass thresholds yields reasonable agreement. Using population synthesis, we find that the shape of the cosmic spectral energy distribution predicted by MBII is consistent with observations, but lower in amplitude. The Galaxy Stellar Mass Function (GSMF) function is broadly consistent with observations at z ≥ 2. At z < 2, observations probe deeper into the faint end and the population of passive low mass (for M * < 10 9 M ) galaxies in the simulation makes the GSMF too steep. At the high mass end (M * > 10 11 M ) galaxies hosting bright AGN make significant contributions to the GSMF. The quasar bolometric luminosity function is also largely consistent with observations. We note however that more efficient AGN feedback (beyond simple thermal coupling used here) is likely necessary for the largest, rarest objects/clusters at low redshifts.

Context. Studying the trajectories of objects like stars, globular clusters, or satellite galaxies in the Milky Way allows the dark matter halo to be traced but requires reliable models of its gravitational potential. Aims. Realistic, yet simple and fully analytical, models have already been presented in the past. However, improved, as well as new, observational constraints have become available in the meantime, calling for a recalibration of the respective model parameters. Methods. Three widely used model potentials are revisited. By a simultaneous least-squares fit to the observed rotation curve, in-plane proper motion of Sgr A*, local mass/surface density, and the velocity dispersion in Baade's window, parameters of the potentials are brought up-to-date. The mass at large radii -in particular, that of the dark matter halo -is hereby constrained by requiring that the most extreme known halo, blue horizontal-branch star has to be bound to the Milky Way. Results. The Galactic mass models are tuned to yield a very good match to recent observations. The mass of the dark matter halo is -within the limitations of the applied models -estimated in a fully consistent way. As a first application, the trajectory of the hypervelocity star HE 0437-5439 is investigated again to check its suggested origin in the Large Magellanic Cloud (LMC). Conclusions. Despite their simplicity, the presented Milky Way mass models are very able to reproduce all observational constraints. Their analytical and simple form makes them ideally suited for fast and accurate orbit calculations. The LMC cannot be ruled out as HE 0437-5439's birthplace.

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