Direct formation of massive black holes via dynamical collapse in metal-enriched merging galaxies at $z \sim 10$: fully cosmological simulations

Understand

We present the results of the first fully cosmological hydrodynamical simulations studying the merger-driven model for massive black hole (BH) seed formation via direct collapse.

• Using the zoom-in technique as well as particle splitting, we achieve a final spatial resolution of $2$ pc.
• We show that the major merger of two massive galaxies at redshift $z \sim 8$ results in the formation of a nuclear supermassive disk (SMD) of only $4$ pc in radius, owing to a prodigious gas inflow sustained at $100$-$1000$ $M_{\odot}$ yr$^{-1}$.
• The core of the merger remnant is metal-rich, well above solar abundance, and the SMD reaches a gaseous mass of $3 \times 10^8$ $M_{\odot}$ in less than a million years after the merger, despite a concurrent prominent nuclear starburst.