An efficient hybrid method to produce high resolution large volume dark matter simulations for semi-analytic models of reionisation

Yisheng Qiu; Simon J. Mutch; Pascal J. Elahi; Rhys J. J. Poulton; Chris Power; J. Stuart B. Wyithe

doi:10.1093/mnras/staa3261

paper

An efficient hybrid method to produce high resolution large volume dark matter simulations for semi-analytic models of reionisation

arXiv:2007.14624 · doi:10.1093/mnras/staa3261

Abstract

Resolving faint galaxies in large volumes is critical for accurate cosmic reionisation simulations. While less demanding than hydrodynamical simulations, semi-analytic reionisation models still require very large N-body simulations in order to resolve the atomic cooling limit across the whole reionisation history within box sizes $≳ 100 h^{- 1} Mpc$ . To facilitate this, we extend the mass resolution of N-body simulations using a Monte Carlo algorithm. We also propose a method to evolve positions of Monte Carlo halos, which can be an input for semi-analytic reionisation models. To illustrate, we present an extended halo catalogue that reaches a mass resolution of $M_{halo} = 3.2 \times 1 0^{7} h^{- 1} M_{⊙}$ in a $105 h^{- 1} Mpc$ box, equivalent to an N-body simulation with $\sim 680 0^{3}$ particles. The resulting halo mass function agrees with smaller volume N-body simulations with higher resolution. Our results also produce consistent two-point correlation functions with analytic halo bias predictions. The extended halo catalogues are applied to the \textsc{meraxes} semi-analytic reionisation model, which improves the predictions on stellar mass functions, star formation rate densities and volume-weighted neutral fractions. Comparison of high resolution large volume simulations with both small volume or low resolution simulations confirms that both low resolution and small volume simulations lead to reionisation ending too rapidly. Lingering discrepancies between the star formation rate functions predicted with and without our extensions can be traced to the uncertain contribution of satellite galaxies.

arXiv comment15 pages, 15 figures. Accepted for publication in MNRAS

An efficient hybrid method to produce high resolution large volume dark matter simulations for semi-analytic models of reionisation

Abstract

References in corpus (53)

Cited by in corpus (5)