2021/11/30 by Simeon Bird, Yueying Ni, Tiziana Di Matteo +3 · 1 citation
Physics and Astronomy · #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stac648
15 pages, 12 figures. Accepted by MNRAS, added star formation rate density
arxiv created 2022/03/23 · arxiv updated 2022/03/24
We introduce the ASTRID simulation, a large-scale cosmological hydrodynamic simulation in a 250 Mpc/h box with 2× 55003 particles. ASTRID contains a large number of high redshift galaxies, which can be compared to future survey data, and resolves galaxies in halos more massive than 2× 109 M_\odot. ASTRID has been run from z=99 to z=3. As a particular focus is modelling the high redshift Universe, it contains models for inhomogeneous hydrogen and helium reionization, baryon relative velocities and massive neutrinos, as well as supernova and AGN feedback. The black hole model includes mergers driven by dynamical friction rather than repositioning. We briefly summarise the implemented models, and the technical choices we took when developing the simulation code. We validate the model, showing good agreement with observed UV luminosity functions, galaxy stellar mass functions and specific star formation rates. We show that the redshift at which a given galaxy underwent hydrogen reionization has a large effect on the halo gas fraction. Finally, at z=6, halos with M ∼ 2× 109 M_\odot which have been reionized have a star formation rate 1.5 times greater than those which have not yet been reionized.