The optimal gravitational softening length for cosmological N-body simulations

Zhang, Tianchi; Liao, Shihong; Li, Ming; Gao, Liang

doi:10.1093/mnras/stz1370

The optimal gravitational softening length for cosmological N-body simulations

Zhang, Tianchi; Liao, Shihong; Li, Ming; Gao, Liang

Authors

Tianchi Zhang

Shihong Liao

Ming Li

Liang Gao

Abstract

Gravitational softening length is one of the key parameters to properly set up a cosmological N-body simulation. In this paper, we perform a large suit of high-resolution N-body simulations to revise the optimal softening scheme proposed by Power et al. (P03). Our finding is that P03 optimal scheme works well but is over conservative. Using smaller softening lengths than that of P03 can achieve higher spatial resolution and numerically convergent results on both circular velocity and density profiles. However using an over small softening length overpredicts matter density at the inner most region of dark matter haloes. We empirically explore a better optimal softening scheme based on P03 form and find that a small modification works well. This work will be useful for setting up cosmological simulations.

Citation

Zhang, T., Liao, S., Li, M., & Gao, L. (2019). The optimal gravitational softening length for cosmological N-body simulations. Monthly Notices of the Royal Astronomical Society, 487(1), 1227-1232. https://doi.org/10.1093/mnras/stz1370

Journal Article Type	Article
Acceptance Date	May 7, 2019
Online Publication Date	May 17, 2019
Publication Date	Jul 31, 2019
Deposit Date	Jul 30, 2019
Publicly Available Date	Jul 30, 2019
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	487
Issue	1
Pages	1227-1232
DOI	https://doi.org/10.1093/mnras/stz1370

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This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2019 The Author[s]. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.