Seeding High Redshift QSOs by Collisional Runaway in Primordial Star Clusters

Understand

We study how runaway stellar collisions in high-redshift, metal-poor star clusters form very massive stars (VMSs) that can directly collapse to intermediate-mass black holes (IMBHs).

• We follow the evolution of a pair of neighbouring high-redshift mini-haloes with high-resolution, cosmological hydrodynamical zoom-in simulations using the adaptive mesh refinement code RAMSES combined with the non-equilibrium chemistry package KROME.
• The first collapsing mini-halo is assumed to enrich the central nuclear star cluster (NSC) of the other to a critical metallicity, sufficient for Population II (Pop.
• II) star formation at redshift $z\approx27$.