The MassiveBlack-II simulation: the evolution of haloes and galaxies to z ∼ 0

Abstract

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.

Scaling relations between black holes and their host galaxies: comparing theoretical and observational measurements, and the impact of selection effects

“…In this paper we use a cosmological hydrodynamic simulation MassiveBlackII (Khandai et al 2014). This simulation is similar (in terms of the physics modelled) to the high-redshift 533 h −1 Mpc MassiveBlack simulation, using a smaller (100 h −1 Mpc) box, but allowing for higherresolution and a complete run to z ∼ 0 (see Table 1).…”

“…In the local universe, the discovery of close relationships between the masses of supermassive black holes and several properties of their bulges such as the stellar mass (Magorrian et al 1998 (2013), and the concentration parameter (Graham et al 2001) have revolutionized our view of BHs, linking their growth to that of its host galaxy (for a recent review see also Kormendy & Ho 2013). Most recently, McConnell & Ma (2013) have re-analyzed the scaling relations and added a number of high mass objects.…”

“…Here we use state-of-the-art cosmological hydrodynamical simulations of structure formation (MassiveBlack-II) (Khandai et al 2014) to investigate the predictions of the galaxy-black hole relations MBH − σ, MBH − M * ,tot and MBH − LV,tot relations for the population of black holes and compare them to the observational constraints at z = 0 − 2. MBII is a recent large-scale and high resolution hydrodynamic simulation in a box of 100Mpc/h on the side, making one of the largest cosmological Smooth Particle Hydrodynamics (SPH) simulation to date with full physics of galaxy formation (meaning here an inclusion of radiative cooling, star formation, black hole growth and associated feedback physics).…”

“…We concentrate on the prediction for the black holegalaxy relations relative to the the total stellar mass and luminosity of the host galaxy as measured by Merloni et al (2010); Bennert et al (2010Bennert et al ( , 2011b; Kormendy & Ho (2013); Park et al (2014). The predictions from the simulations are most direct for the total quantities (stellar mass and luminosity) and we do not need to indroduce unknown biases as we would have if we used proxies for these measurements in galaxy bulge components (we reserve this work to a future analysis with morphological decomposion).…”

The rise and fall of stellar across the peak of cosmic star formation history: effects of mergers versus diffuse stellar mass acquisition

“…Hence one needs to asses the relative importance of mergers versus smooth accretion driven by the cosmic environment and to study its induced morphological diversity. With the advent of large-scale albeit fairly well resolved cosmological hydrodynamical simulations such as Horizon-AGN , see as well Devriendt et al 2010;Khandai et al 2014;Vogelsberger et al 2014;Schaye et al 2015 for similar simulations performed with different numerical techniques), it has recently become feasible to investigate these different physical processes in detail and with sufficient statistics, a necessary requirement to truly unravel the impact of galaxy environment on their properties.…”