NEMO - A Stellar Dynamics Toolbox
As of 21-dec-2017 see our
github pages for the 4.0 release
For the regulars: keep reading the
What's New , the
What's Up , and the
What's Down memos in NEMO!
What is NEMO?
is an extendible Stellar Dynamics Toolbox, following an
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
The source code consist of
a little over 4000 files and a little under 1,000,000
lines of code and documentation, mostly C, and some
C++ and Fortran.
We also advertise
other software packages , which work on similar problems. NEMO
development started in 1986 in Princeton (USA) by Barnes, Hut and Teuben.
NEMO is also in ASCL,
The following manuals and documents describe various aspect of NEMO.
The hypertext versions were compiled with automated tools, and may not
all be in great shape, however, for all of them fine looking postscript
files are available.
images which can be generated with NEMO
are shown here. Most
of them have clickable images, which may take some time loading, and
they may not be as pretty as they appear on the screen, but give you an
idea of the kind of environment NEMO offers.
In addition a
Snapshot Data Archive of interesting simulations
are now available.
Papers that discuss Stellar Dynamics Software can be found in:
If you acknowledge the use of NEMO, and want to refer to
a publication, this is the most current one:
- On Toolboxes and Telescopes , by
Hut and Sussman, (1986)
in: The Use of Supercomputers in Stellar Dynamics,
Springer Verlag, p 193-198.
- An Environment for Experiments in
Stellar Dynamics , by:
Barnes, Hernquist, Hut and Teuben (1988) BAAS, 20, 706.
- A Laboratory for Gravitational
Scattering Experiments by Hut, in: IAU colloq 109,
- NEMO: A Stellar Dynamics Toolbox ,
by Teuben (1994, PASJ, xxx, yyy) overviews the current state of
NEMO and introduces a proposal to use
FITS as a vehicle to interchange and archive NBODY data
(see also the QUESTIONNAIRE ).
A gzip compressed
of this paper is also available.
Sci.Data.Formats FAQ discussion may be relevant.
The example program mentioned in
an NBODY BINTABLE .
- ADASS (1994) paper ,
adass.org version. I also keep a
postscript version around.
- GRAPE User Workshop
- other miscellaneous papers
Teuben, P.J. The Stellar Dynamics Toolbox NEMO, in:
Astronomical Data Analysis Software and Systems IV,
ed. R. Shaw, H.E. Payne and J.J.E. Hayes. (1995),
PASP Conf Series 77, p398.
I appreciate if authors could send me a reference of any paper
in which NEMO has been used.
The NEMO anonymous ftp directory
has the following to offer:
Difficulties during installation are most likely resolved by consulting
Appendix G in the (rather large)
and checking last minute changes that are
discussed in the $NEMO/README file.
also pick up some hints from my NEMORC.local
- The now recommended CVS based installation. You can browse
some example scripts in the install scripts
directory, this is the basic 3 lines:
tar zxf nemo_cvs.tar.gz
# or combine these two with this one-liner (wget also has a similar mode):
curl ftp://ftp.astro.umd.edu/pub/nemo/nemo_cvs.tar.gz | tar zxf -
# wget could need --active-ftp, since --passive-ftp is default
# curl has a similar option, --ftp-pasv
cvs login ; cvs update -d # just to be sure to be up to date
and you should have a working NEMO with PGPLOT as the plotting
- There are a number of optional libraries you will need to install
all of the programs:
- pgplot or plplot (with this X11 of course)
- rdl (readline)
- automatic build logfile of NEMO are
now produced as soon as new code has been checked into CVS.
- , a (normally
file, that contains the latest official release.
Note this contains a full src tree, and small sections
of the so-called usr tree.
If you plan to use a stable NEMO and probably won't upgrade for a while,
this would be the recommended path of installing.
- Some older MacOSX related installation notes,
although the regular installation method should work fine as long
as you have compilers and various external libraries (notably X11) installed.
- You can also download the latest
nemo_cvs.tar.gz , which is an anonymous-
directory tree. Just install it as usual (i.e. read the
blurbs in the file INSTALL).
If you want
bleeding edge (read: fast and reliable) updates, this
command will do it:
cd $NEMO ; make cvslogin # one time setup
cvs -n -q update # check what's new, locally
cvs update -d -P # update the tree locally
We currently don't use any
CVS branching, just a single mainline CVS.
After this you can update your libraries/programs, e.g.
cd $NEMO ; make libs # redo libraries, if needed
mknemo tsf mkplummer .... # relink selected binaries
If you plan to use NEMO in any development way, this would be the recommended
path of installing. If you prefer to stay more "stable", you can
always use our tagnames to update only to the most recent update, e.g.
cvs update -r nemo_3_0_16
i.e. replace the dot with an underscore in your VERSION. Notice
that this operation will create sticky tags, if you change
a file for your own purporse, CVS will flag you a conflict.
- A binary release of NEMO is also available within
download astromake and update via the astromake
procedure, or download the binary from
, the last patch tarfile that
was made. This patch file can be updated several times, until
the next patchlevel has come out. If the patch level is the
same as that export version there is no reason
to get this now-old patch file. This patch file should
be untarred in the $NEMO directory.
Aarseth's nbody0. Although the source code is
taken directly from NEMO, the Makefile contains
targets to create standalone versions, both in FORTRAN-77
(the exact copy from Binney & Tremaine, 1st Ed), and a C version.
A very popular item to download, hence also available
"standalone". See also
Sverre's anonymous ftp
for the more advanced versions. NEMO also contains nbody1 and
nbody2 with NEMO interfaces.
NEMO nbody fits proposal (This is now an outdated version,
please refer to the
1994 PASJ paper
automatic GUI builder and frontend to run shell scripts or programs.
- optional software that can be installed
to enrich NEMO (this is where you find links to PGPLOT, HDF, CFITSIO etc.)
Linux for Astronomy CD-ROM contains a release of NEMO. Also
check latest LFA comments.
If you download NEMO, we ask that you register the software, you can also
optionally be notified of new releases, but please:
Send us an email!
Other software, that we know of, that deal with particle simulations, are
(apologies if the URL appears outdated, that's a fact of life these days):
Some time ago a discussion took place on if to
choose an N-body Data Interchange Format, and if so, which.
An e-mail exploder was installed to act as a
discussion forum, and
are archived locally and elsewhere. Currently, this interest has shifted
Virtual Observatory (TVO) .
NEMO is maintained by
Peter Teuben .
He works in the
Laboratory for Millimeter-Wave Astronomy , part of
BIMA , now
Astronomy Department of the
University of Maryland in
MD (USA) -
- STARLAB ;
created by Piet Hut, Steve McMillan and Jun Makino, was loosely modeled
is NEMO's close relative; created by
(he also maintains an
anonymous ftp directory with updated versions
of the treecode in C as well as fortran, see also his
The Art of Computational Science,
A series of e-books on how to build a computational lab (Hut & Makino) -
alos has lots of code and examples available.
an interactive X-windows based display package maintained by
Neal Katz and Tom Quinn. Their
also maintains a
You should also read about their
N-Chilada visualization and analysis software SALSA
- partiview, a 4D (space and time) OpenGL-based
visualization tool that also understand starlab data.
(Gnedin's general purpose visualization utility)
a software framework for large-scale simulations of dense stellar systems,
in which existing codes for dynamics, stellar evolution, hydrodynamics
and radiative transfer can be easily coupled.
initialconditions.org, a blog on Astrophysical
Initial conditions (for the N-body problem).
- pynbody, a
framework for N-body and SPH astrophysical simulations, written in python.
A Multi Dimensional visualization and analysis toolkit for astrophysics.
Gravit, gravity simulator
with viewing of orbit histories. Uses OpenGL/SDL.
gravity and electromagnetism simulator
modelling planatary systems, including replicating the orbits of moons
around planets while those planets orbit a central sun.
a cross platform concurrent n-body modelling framework written in C++.
- John Salmon's home page,
which pointers and references to parallel treecodes.
- John Fregeau's
fewbody and glstarview
Bill Rankin's implementation of the Fast Multipole Algorithm.
(see also NAMD)
ENZO (Terascale application for cosmological hydrodynamics)
(Paul Bode's Tree-Particle-Mesh code)
Volker Springer's and Naoki Yoshida's tree-code for (cosmological) N-
body/SPH simulations .
StarCrash, an parallel SPH code.
MLAPM: Alexander Knebe's recursively refined Cartesian grid code.
A new version under the name
AMIGA is now available.
Rainer Spurzem's version of
NBODY6++ can be downloaded from this
Silk Road Project site. There's a
wiki page on it as well, though will migrate to its
new location later in 2012.
Also some interesting
glnemo is an interactive visualization 3D program, using Qt,
that comes with NEMO. This has now been superseded by
Xnbody: an online visualization tool for nbody6++
Walter Dehnen's new and Very Fast and Momentum-Conserving Tree Code.
It was first
introduced in NEMO as YancNemo, but later renamed to
(Numerical Algorithms for General Body Dynamics) , an N-body
code plus toolset by Mario Alberto Rodriguez-Meza
PMFAST particle-mesh N-body code (f90) with MPI/OpenMP.
HNBody Symplectic Integration Package (Rauch & Hamilton)
A solar system integration software package (Levison/Duncan).
Anatoly Klypin's PM code. See also their
home page. His adaptive P3M code (
A3PM) is also available with a
NEMO frontend in (pstart,
prun). See also
Manual also available from
- The XStar N-body Solver
Purveyors of fine N-body algorithms and simulation data,
UK mirror), provide public domain software and data for
N-body hydrodynamical simulations.
New pages (Spring 2000) are now at:
VIRGO, a consortium of a number of N-Body related
key projects, including a page with
Software, and now
Sverre Aarseth's collection of nbody codes.
Douglas Heggie's homepage
contains the material for
A collaborative experiment on star cluster evolution
- Sverre's new interactive movie website
Derek Richardson's web-page contains the
Box Tree Code as well as xa, an X11 animation tool.
Galactic Collider, interactive Toomre-type galaxy collisions.
plotting and manipulating 3D particle distributions with PGPLOT
- The N-Body Site,
Ben Moore's compilation (formerly www.nbody.net) with
lots of pictures and movies.
Galaxy Dynamics N-Body Simulations (Jakub Schwarzmeier's self-teaching project)
Leiden Dynamics Group is also maintaining a software page.
The Texas P3M Database, a database of COBE-Normalized CDM Simulations.
Send email to
firstname.lastname@example.org if you want any of their 68 models.
Their abbreviated paper is available on
ASTRO-PH, and there
are routines within NEMO to read the data.
Mark Bellon's N-body solver.
Mark Ridler's grav-sim simulator
FLASH (also incoorporates
poisson solvers). See also
COSMOS, a Fortran 90 code for parallel computers that solves the
evolution equations for gravitationally coupled gas and collisionless
matter in one, two, or three dimensions.
NBodyLab Stellar Dynamics Simulation Testbed
a particle based astrophysical simulation code using a tree structure
and SPH for gas dynamical effects.
(Orbit Reconstruction, Simulation and Analysis).
Java Applet for Gravitational Orbit Simulation (includes source code)
TRIP : a general computer algebra system dedicated to celestial mechanics.
(Laskar and Gastineau)
- IASG :
Kavan Ratnatunga's Galactic Structure
Analysis package. It contains a modified version of the
Bahcall-Soneira Galaxy model .
developed by John Dubinski and Konrad Kuijken,
for generating N-body realizations of axisymmetric
galaxy models consisting of disk, bulge and halo.
We keep a local copy within in NEMO in standard Fortran,
so it also compiles under Linux.
Chris Mihos' Models of Merging Galaxies.
Laboratory for Computational Astrophysics (LCA) maintains
an archive of their
codes and documentation .
Grand Challenge Cosmology Consortium (GC3) figures out
the origin of large scale structure in the universe. They have a
software archive , a
data archive , and lot's of other interesting pages and links.
- The GalMer database contains
many galaxy merger simulations.
COSMICS and Grafic (Cosmological Initial Conditions Codes) (Bertschinger)
- GRACOS, a parallel cosmological N-body code (Shirokov/Bertschinger)
Sirko's Cosmological Initial conditions
Multi-body Gravity Simulator(MGS), A java-3d based package
to perform realtime simulations, three dimensional visualizations,
design simulations in XML and with a GUI.
(Warsaw University Observatory)
Smooth Particle Hydrodynamics
list, part of the CFD codes list document,
which is regularly posted to the
sci.physics.computational.fluid-dynamics newsgroup .
current list is now maintained by Wayne Christopher. It
also included Greg Lindahl's
- astrophysical simulation codes
a toolkit for the simulation of the passage of particles through matter.
IDL Astronomy User's Library has some routines to aid in
plotting N-body systems.
Marc Davies' IDL resources)
Particula Numerica, a real-time Gravitational N-Body Simulator. (mac/windows)
- galaxy, a free
linux program which simulates the motion of stars under the influence of gravity.
- PC-Based programs
is a PC-based simulation of interacting galaxies
written by Christian Sturm.
Galaxy software (also has a cool interactive web based tool)
Astronomy Software from
Zephyr. They have several programs
with which N-body systems can be created and evolved, but expect
to pay some money.
- Animations (you probably need to have
and other pretty pictures:
- Some Related Fields
- Fast, Free and Flexible MD
and their wiki
Molecular Dynamics Vizualisation.
- MDBNCH ,
A molecular dynamics benchmark.
- AMBER, a molecular dynamics
LASSPTools is a collection of Unix utilities for numerical
analysis and graphics, built very much in the philosophy of NEMO,
and may be useful in NEMO shell scripts.
vizualization and selecting data from general multi-variate data.
(see also: ggobi, mirage)
- Some software information banks that may be relevant:
(Astronomical Software & Documentation Service)