gadget

A code for collisionless and gas dynamical cosmological simulations

Version : 1.1
Author(s) : Volker Springel (vspringel@cfa.harvard.edu) , Naoki Yoshida (naoki@mpa-garching.mpg.de)
License : GPL
Website : http://www.mpa-garching.mpg.de/gadget/

Installs from Open Source Astronomy for Linux cd 3
Disk space required for installation is 23.32 Mb

Screenshots

The following printable documents will be installed :

Summary

In its current implementation, the serial and parallel versions of GADGET (GAlaxies with Dark matter and Gas intEracT1) support collisionless simulations and smoothed particle hydrodynamics on serial or massively parallel computers. While the parallel code required substantial changes in certain parts of the computational algorithms, we have nevertheless tried to keep the structure of the two codes, and their usuage, as similar as possible. In principle, it would be possible to merge the codes into one source, and employ large numbers of compiler directives to generate serial or parallel behaviour as desired. However, we think that would make the code much more opaque, and would compromise one of our objectives, which is to provide a clean, well-documented code that can be easily understood and modified by users. We therefore provide two separate versions of the code, one for serial and one for parallel computations.

The code can be used for plain Newtonian dynamics, or for cosmological integrations in arbitrary cosmologies, both with or without periodic boundary conditions. The modeling of hydrodynamics is optional. The code is fully adaptive both in space and in time.

The main reference for numerical and algorithmic aspects of the code is the paper `GADGET: A code for collisionless and gas-dynamical cosmological simulations', Springel, Yoshida & White, 2000, submitted to New Astronomy (see preprint at astro-ph/0003162). In the following, this paper will be frequently referenced, and I recommend reading it before you attempt to use the code.

Features

Hierarchical multipole expansion (tree method) for gravitational forces (geometrical oct-tree, Barnes&Hut-style)

Optional periodic boundary conditions (Ewald summation technique)

Smoothed particle hydrodynamics with fully adaptive smoothing lengths

Shear-reduced artificial viscosity

Individual timesteps of arbitrary size for all particles

Work-load balancing and dynamic tree updates

Efficient cell-opening criteria

Highly efficient integrator in the linear regime of gravitational clustering

Flexible control of all code options by a free-format parameterfile

Portable, well documented code, relying only on standard language/communication features

High raw computational speed and good scalability