Open Accessgrommet : an N ‐body code for high‐resolution simulations of individual galaxies
Author(s) -
Magorrian John
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.12344.x
Subject(s) - physics , galaxy , halo , astrophysics , code (set theory) , smoothed particle hydrodynamics , dynamical friction , galactic halo , bar (unit) , classical mechanics , set (abstract data type) , computer science , programming language , meteorology
This paper presents a fast, economical particle‐multiple‐mesh N ‐body code optimized for large‐ N modelling of collisionless dynamical processes, such as black hole wandering or bar–halo interactions, occurring within isolated galaxies. The code has been specially designed to conserve linear momentum. Despite this, it also has variable softening and an efficient block‐time‐step scheme: the force between any pair of particles is calculated using the finest mesh that encloses them both (respecting Newton's third law) and is updated only on the longest time‐step of the two (which conserves momentum). For realistic galaxy models with N ≳ 10 6 , it is faster than the fastest comparable tree code by factors ranging from ∼2 (using single time‐steps) to ∼10 (multiple time‐steps in a concentrated galaxy).