2018/03/14 by Owain Snaith, Owain N. Snaith, Changbom Park +2
Environmental Science · Physics and Astronomy · #Adaptive mesh refinement #Algorithm #Astrophysics #Computational physics #Computer science #Convergence (economics) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Grid #Image resolution #Optics #Physics #Plant Water Relations and Carbon Dynamics #Resolution (logic) #Scientific Research and Discoveries #Star formation #Statistical physics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/sty673
23 pages, 22 figures, 1 table, accepted for publication in MNRAS
openalex publication_date 2018/03/14 · arxiv created 2018/03/21 · arxiv updated 2018/03/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We have explored the evolution of gas distributions from cosmological simulations carried out using the ramses adaptive mesh refinement (AMR) code, to explore the effects of resolution on cosmological hydrodynamical simulations. It is vital to understand the effect of both the resolution of initial conditions (ICs) and the final resolution of the simulation. Lower initial resolution simulations tend to produce smaller numbers of low-mass structures. This will strongly affect the assembly history of objects, and has the same effect of simulating different cosmologies. The resolution of ICs is an important factor in simulations, even with a fixed maximum spatial resolution. The power spectrum of gas in simulations using AMR diverges strongly from the fixed grid approach – with more power on small scales in the AMR simulations – even at fixed physical resolution and also produces offsets in the star formation at specific epochs. This is because before certain times the upper grid levels are held back to maintain approximately fixed physical resolution, and to mimic the natural evolution of dark matter only simulations. Although the impact of hold-back falls with increasing spatial and IC resolutions, the offsets in the star formation remain down to a spatial resolution of 1 kpc. These offsets are of the order of 10–20 per cent, which is below the uncertainty in the implemented physics but are expected to affect the detailed properties of galaxies. We have implemented a new grid-hold-back approach to minimize the impact of hold-back on the star formation rate.