The origin of the most massive black holes at high-z: BlueTides and the next quasar frontier

Abstract

The growth of the most massive black holes in the early universe, consistent with the detection of highly luminous quasars at z > 6 implies sustained, critical accretion of material to grow and power them. Given a black hole seed scenario, it is still uncertain which conditions in the early Universe allow the fastest black hole growth. Large scale hydrodynamical cosmological simulations of structure formation allow us to explore the conditions conducive to the growth of the earliest supermassive black holes. We use the cosmological hydrodynamic simulation BlueTides, which incorporates a variety of baryon physics in a (400h −1 Mpc) 3 volume with 0.7 trillion particles to follow the earliest phases of black hole critical growth. At z = 8 the most massive black holes (a handful) approach masses of 10 8 M with the most massive (with M BH = 4 × 10 8 M ) being found in an extremely compact spheroid-dominated host galaxy. Examining the large-scale environment of hosts, we find that the initial tidal field is more important than overdensity in setting the conditions for early BH growth. In regions of low tidal fields gas accretes 'cold' onto the black hole and falls along thin, radial filaments straight into the center forming the most compact galaxies and most massive black holes at earliest times. Regions of high tidal fields instead induce larger coherent angular momenta and influence the formation of the first population of massive compact disks. The extreme early growth depends on the early interplay of high gas densities and the tidal field that shapes the mode of accretion. Mergers play a minor role in the formation of the first generation, rare massive BHs.

The clustering of z > 7 galaxies: predictions from the BLUETIDES simulation

“…BLUETIDES also consistently predicted the properties of GN-z11 (Oesch et al 2016) which is the farthest galaxy observed to date (Waters et al 2016a). BLUETIDES forecasts for the upcoming WFIRST satellite have been made by Waters et al (2016b) and results look promising with about 10 ume of BLUETIDES it has also been possible to study the formation of the first quasars, supermassive black holes (Di Matteo et al 2017).…”

The z = 7.54 Quasar ULAS J1342+0928 Is Hosted by a Galaxy Merger

“…Our data provide a good test for large cosmological simulations that allow the study and prediction of the observational properties of the first galaxies and supermassive black holes in the universe (e.g., Feng et al 2016;Lupi et al 2019). For example, the brightest quasar in the BlueTides simulation has a similar luminosity and black hole mass at z = 7.54 to J1342+0928 (Di Matteo et al 2017;Tenneti et al 2019), but some of the predictions on the host galaxy of the simulated quasar are different from our findings. Ni et al (2018) find that the simulated BlueTides z = 7.54 quasar produces gas outflows reaching thousands of km s −1 with respect to the systemic redshift, similar to what reported in a quasar at z = 6.4 (Cicone et al 2015).…”

Super-Eddington growth of black holes in the early universe: effects of disc radiation spectra

“…In the recent decade, large-scale cosmological simulations studying galaxy formation and evolution have been carried out intensively, e.g., FIRE (e.g., Hopkins et al 2014), and Illustris (e.g., Vogelsberger et al 2014) simulation. Some simulation studies (e.g., Habouzit et al 2017;Di Matteo et al 2017) focused on the early epoch of the Universe and investigated the relationships between growth of high-z BHs and the properties of their host halos. As a sub-grid model to characterize rapid growth of BHs, the transition conditions would be applicable for those cosmological simulations which do not resolve the Bondi radius of the BHs.…”