A modified version of Galactics that can be used together with Bonsai to generate initial conditions using multiple processes
2015-09-16
This is a modified version of the Galactics package by Dubinski, Kuijken and Widrow the copyright of this package belongs to them.
The changes we made allow us to include the galactics package as library into Bonsai and generate models in parallel on multiple nodes and then combine them into a single large model.
To compile Galactics:
- cd src
- make -f Makefile.[ifort/gnu] use ifort if you have Intel Fortran compiler (3x faster than gfortran), otherwise use Makefile.gnu
- cp libgengalaxy.a ../../ (to link it with Bonsai)
To generate Initial conditions:
Take the following steps:
-
Setup your model as you would normally do in Galactics
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Run make and wait untill the following files are generated: cordbh.dat dbh.dat freqdbh.dat mr.dat denspsibulge.dat denspsihalo.dat
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Once the above files are generated you can interrupt Galactics.
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Copy the above files to the folder from which you run Bonsai
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Modify/create the file 'component_numbers.txt'. This file is used to determine the ratio's between the number of particles in the Halo, Bulge and Disk.
The component_numbers.txt file should contain on the first line three numbers: nHalo nBulge nDisk
Again these numbers will be converted to ratio's based on the actual number of particles that are requested using the Bonsai parameter: --milkyway nParticlesPerNode .
- Now you are ready to run Bonsai and generate the IC
When using this code make sure to cite the original authors:
- Kuijken, K.; Dubinski, J. 1995 (1995MNRAS.277.1341K)
- Widrow & Dubinski 2005 (2005ApJ...631..838W)
- Widrow, Pym and Dubinski 2008 ( 2008ApJ...679.1239W )
Evghenii Gaburov & Jeroen Bédorf
#GalactICS Quickstart Manual
GalactICS is a package for generating realistic models of galaxies that can optionally include a disk, bulge, dark halo and central supermassive blackhole. The code works by running a suite of programmes that compute a gravitational potential for a given mass model, compute a distribution function for each component and then realize these components as independent N-body files that can be joined together to make an N-body model of a galaxy. The computed gravitational potential can also be used as a force field in test particle orbital calculations and other applications.
The physical and mathematical details behind the construction of these models is described in Widrow, L. and Dubinski, J. 2005, ApJ, in press
This is super easy.
- cd src
- make
- make install
This will build the code and copy the binaries to the directory ./bin.
To clean and rebuild just type (make clean; make; make install).
This is best illustrated with the examples of M31 and the Milky Way in the subdirectory ./models. Here you will find a series of input parameter files for various programmes that describe the underlying models. Check the README and README.parameters file in example of M31 for a detailed description of these parameters and how to build a galaxy.
John Dubinski May-31-2005