Massive Star Formation in Overdense Regions of the Early Universe

Both the origin of, and population demographics massive black holes (MBHs) remains an open question in modern day astrophysics. Here we introduce BlackDemon suite of cosmological simulations using Enzo code. The consists primarily three, high resolution, distinct regions, each with a side length 1 h$^{-1}$ Mpc. Two regions evolve within larger overdense region while other evolves more `normal' region. simulation has spatial mass resolution capable resolving formation first galaxies MBHs We report here, as series papers, evolution up to point where star commenced for 2 Myr after onset formation. Within these environments masses objects form have between approximately 100 M$_{\odot}$ $10^4$ M$_{\odot}$. due both major mergers, which trigger rapid inflow centre halo, also through multiple minor mergers allows host halo grow close atomic cooling threshold. In scenarios initially very accretion rates quickly However, halts less than 50,000 years gas starvation. final fate terms fragmentation subsequent fragment cannot be deduced at our current resolution. case is mild such are likely super-massive stars before contracting main sequence evolving into III subsequently MBHs.