Modest 5c: Teachers

Piet Hut (Art of Comp. Science: www.artcompsci.org)

Jun Makino (Art of Comp. Science: www.artcompsci.org)

Douglas Hegie (The Gravitational Million-Body Problem)

Steve Mc Millan (Starlab: www.ids.ias.edu/~starlab)

Peter Teuben (Nemo: http://bima.astro.umd.edu/nemo/)

Simon P. Zwart (Starlab)

Bill Paxton(Stellar Evolution)

James Lombardi (Make Me A Star MMAS)

Modest 5c: Program

08:00-11:00: Work

11:00-12:00: Talks

12:00-16:00: Work

16:00-17:00: Discussion

17:00-19:00: Work

Modest 5c: Results

Install software (Nemo, Starlab, partiview)

Learning about existing codes

Various projects (20)

Wiki page (www.science.uva.nl/sites/modesta/wiki/index.php/List_of_projects)

Modest 5c: Nemo

“NEMO is an extendible Stellar Dynamics Toolbox, following the Open-Source Software model. It has various programs to create, integrate, analyze and visualize N-body and SPH like systems, following the pipe and filter architecture. In addition there are various tools to operate on images, tables and orbits, including FITS files to export/import to/from other astronomical data reduction packages. A large growing fraction of NEMO has been contributed by a growing list of authors. The source code consist of a little under 1000 files and 150,000 lines of code, mostly C, and some C++ and Fortran. We also advertise other software packages , which work on similar problems.”

Nemo

http://bima.astro.umd.edu/nemo

Collection of 250+ programs running under standard Unix Shell, each performing a small task controlled by a set of parameters

It has various groups of programs for creating initial data, integrating and plotting data

N-body group: it consists of programs to create N-body systems (spherical, disk), methods to compute the gravitational field (softened Newtonian, hierarchical) and time integrators (leapfrog, Runge-Kutta).

Orbit group: it consists of programs to calculate an individual orbit in a static potential and analyze it. For example in an N-body system, the system can be freezed at a certain time and the path of a single body can be calculated in the gravitational potential.

Image group: it consists of programs to create images from snapshots

Nemo: Initial data

Plummer model: mkplummer

Cube: mkcube

Spiral: mkspiral

mkbaredisk, mkdisk etc.

Nemo: Integrators

firstn

nbody0, nbody00: Direct N-body integrator. Each particle has its own integration time step. Interactions per time step: O(N*N). Appendix 4B of Binney & Tremaine (1987)

nbody1,2,4,6: Aarseth 2004

nbody6++: an MPI version of nbody6

hackcode1,3: hierarchical N-body code with equal timesteps. It uses adaptive Eulerian tree to reduce the number of interactions per time step to O(Nlog(N)). J. Barnes and P. Hut, Nature 324, 446

Nemo: Plotting

xyzview

snap3d

partiview: an out-of-Nemo package

Starlab

“Starlab is a software package for simulating the evolution of dense stellar systems and analyzing the resultant data. It is a collection of loosely coupled programs (``tools'') linked at the level of the UNIX operating system. The tools share a common data structure and can be combined in arbitrarily complex ways to study the dynamics of star clusters and galactic nuclei.”

Starlab: features

Three- and four-body automated scattering packages, constructed around a time-symmetrized Hermite integration scheme.

A collection of initialization and analysis routines for use with general N-body systems.

A general Kepler package for manipulation of two-body orbits.

N-body integrators incorporating both 2nd-order leapfrog and 4th-order Hermite integration algorithms.

Kira, a general N-body integrator incorporating recursive coordinate transformations, allowing uniform treatment of hierarchical systems of arbitrary complexity within a general N-body framework (versions 2.1 and above).

SeBa, a stellar and binary evolution package, allowing to follow in time the evolution of any star or binary from arbitrary start conditions. The package is fully implemented within kira in a comprehensive and transparent fashion (versions 3.0 and above).

Starlab:

Starlab: www.ids.ias.edu/~starlab/

Starlab tools: www.ids.ias.edu/~starlab/tools/

Kira integrator: www.ids.ias.edu/~starlab/kira/

SeBa: www.ids.ias.edu/~starlab/seba/

Starlab classes and libraries: www.ids.ias.edu/~starlab/libraries

Starlab: Initial data

Plummer model: makeplummer, add_plummer

King model: makeking

Cube: makecube

Disk: makedisk

Etc

makemass gives to the particles a mass distribution

Starlab: Integrators

leapfrog: Integrates using the leapfrog method

kira: It is a fourth-order, individual-timestep ``Hermite'' predictor-corrector scheme (Makino and Aarseth 1992)

kira_harp3: a GRAPE version of kira

SeBa: It gives the evolution of single stars or binaries and togeather with kira they can give the dynamical and stellar evolution of a cluster

Starlab: plotting etc

xstarplot, xstarplot22, starplot

other:

scatter3: performs 3-body scattering experiments

sigma3: calculates cross sections for 3-body scattering experiments

etc

2005-08-22T09:29:03