An improved SPH scheme for cosmological simulations

By A. Beck, Giuseppe Murante, Alexander Arth, R. Remus, Adelheid F. Teklu, Julius Donnert, S. Planelles, Marcus C. Beck, P. Förster, Maximilian Imgrund and 2 more. 2015

168 citations recorded by the source corpus.

We present an implementation of smoothed particle hydrodynamics (SPH) with improved accuracy for simulations of galaxies and the large-scale structure. In particular, we implement and test a vast majority of SPH improvement in the developer version of GADGET-3. We use the Wendland kernel functions, a particle wake-up time-step limiting mechanism and a time-dependent scheme for artificial viscosity including high-order gradient computation and shear flow limiter. Additionally, we include a novel prescription for time-dependent artificial conduction, which corrects for gravitationally induced pressure gradients and improves the SPH performance in capturing the development of gas-dynamical instabilities. We extensively test our new implementation in a wide range of hydrodynamical standard tests including weak and strong shocks as well as shear flows, turbulent spectra, gas mixing, hydrostatic equilibria and self-gravitating gas clouds. We jointly employ all modifications;however, when necessary we study the performance of individual code modules. We approximate hydrodynamical states more accurately and with significantly less noise than standard GADGET-SPH. Furthermore, the new implementation promotes the mixing of entropy between different fluid phases, also within cosmological simulations. Finally, we study the performance of the hydrodynamical solver in the context of radiative galaxy formation and non-radiative galaxy cluster formation. We find galactic discs to be colder and more extended and galaxy clusters showing entropy cores instead of steadily declining entropy profiles. In summary, we demonstrate that our improved SPH implementation overcomes most of the undesirable limitations of standard GADGET-SPH, thus becoming the core of an efficient code for large cosmological simulations.

Subfields: Astronomy and Astrophysics, Computational Mechanics

View Paper: https://www.semanticscholar.org/paper/565e4af4ecbda23d2951e22877cd710ee41bcbdc

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Citations in the corpus

Gasoline2: a modern smoothed particle hydrodynamics code (2017, background): “Many codes include a combination of these features (e.g. the GADGET derived codes of Hu et al. 2014 and Beck et al. 2016).”
CONNECTING ANGULAR MOMENTUM AND GALACTIC DYNAMICS: THE COMPLEX INTERPLAY BETWEEN SPIN, MASS, AND MORPHOLOGY (2015, methodology): “It includes various updates in the formulation of SPHregarding the treatment of the viscosity and the used kernels (see Dolag et al. 2005; Donnert et al. 2013; Beck et al. 2015).”
Baryon impact on the halo mass function: Fitting formulae and implications for cluster cosmology (2015, background): “…2002) and a higher order kernel based on the biascorrected, sixth-order Wendland kernel (Dehnen & Aly 2012) with 295 neighbours, which together with a low-viscosity SPH scheme allows us to properly track turbulence within galaxy clusters (Dolag et al. 2005; Donnert et al. 2013; Beck et al. 2016).”
Phantom: A Smoothed Particle Hydrodynamics and Magnetohydrodynamics Code for Astrophysics (2017, background): “Almost all of these have since been implemented in development versions of Gadget-3 (e.g. Iannuzzi & Dolag 2011; Beck et al. 2016; see recent comparison project by Sembolini et al. 2016) but remain unavailable or unused in the public version.”
The EAGLE simulations of galaxy formation: the importance of the hydrodynamics scheme (2015, background): “…controlled tests such as Sedov explosions or Kelvin-Helmoltz instabilities (e.g. Price 2008; Read et al. 2010; Springel 2010b; Hu et al. 2014; Hopkins 2015; Beck et al. 2015) enables the simulator to identify wellmotivated values for the parameters and understand the limitations of the formulation.”