Speaker
Dr
Taysun Kimm
(KICC and IoA, University of Cambridge)
Description
Reionisation in the early universe is likely driven by LyC photons from dwarf galaxies. Using high-resolution, cosmological radiation-hydrodynamic simulations, we study the escape of LyC photons from mini-haloes with the mass Mhalo < 1e8 Msun. Our simulations include a new thermo-turbulent star formation model, non-equilibrium photo-chemistry, and important stellar feedback processes (photo-ionisation by young massive stars, radiation pressure from UV and IR photons, and mechanical supernova explosions). We find that the photon number-weighted mean escape fraction in mini-haloes is higher than that in atomic-cooling haloes, although the instantaneous fraction in individual haloes varies significantly. Because star formation is very stochastic and dominated by a single or a few gas clumps, the escape fraction is generally determined by radiation feedback, rather than supernova explosions. Interestingly, the resulting stellar mass of the proto-galaxies in the mini-halos is found to follow the empirical stellar mass-to-halo mass relation in the local Universe. We discuss the importance of the photons from mini-haloes for reionisation of the universe.
Author
Dr
Taysun Kimm
(KICC and IoA, University of Cambridge)
