MASC

MASC (Make a star cluster) is an AMUSE-based script to generate a star cluster, to be used in N-body simulations or for other purposes. It aims to include all popular distribution models, initial mass functions, and many more features.

Supported features

• Stellar distributions: Plummer, King, fractal-based
• Initial mass function: Salpeter, Kroupa, equal-mass
• Metallicity
• Virial ratio

Not yet supported features

• Stars in initial binary/triple/multiple configurations
• Other particles than stars

Requirements

MASC requires AMUSE (https://github.com/amusecode/amuse) to work.

Usage:

Package version:

from amuse.units import units
from amuse.ext.masc import new_star_cluster
cluster = new_star_cluster(
    number_of_stars=1024,
    # stellar_mass=False,
    initial_mass_function='salpeter',
    upper_mass_limit=125.0 | units.MSun,
    effective_radius=3.0 | units.parsec,
    star_distribution='plummer',
    # star_distribution_w0=7.0,
    # star_distribution_fd=2.0,
    star_metallicity=0.01,
)

Standalone version:

$ python make_a_star_cluster.py -h
usage: make_a_star_cluster.py [-h] [-o CLUSTERNAME] [-type FILE TYPE]
                              [-N NUMBER_OF_STARS] [-M CLUSTER_MASS]
                              [-dist STAR_DISTRIBUTION]
                              [-gasdist GAS_DISTRIBUTION]
                              [-imf INITIAL_MASS_FUNCTION]
                              [-modelnr CLUSTER_MODEL_NUMBER]
                              [-kingw KING_PARAMETER_W0]
                              [-fractald FRACTAL_PARAMETER_FD]
                              [-uml UPPER_MASS_LIMIT] [-Z METALLICITY]
                              [-ibf INITIAL_BINARY_FRACTION]
                              [-R EFFECTIVE_RADIUS] [-vr VIRIAL_RATIO]

optional arguments:
  -h, --help            show this help message and exit
  -o CLUSTERNAME        Outputfile name [auto]
  -type FILE TYPE       Output file type ([amuse]/ascii/starlab/nemo)
  -N NUMBER_OF_STARS    Number of stars
  -M CLUSTER_MASS       Cluster mass (takes precedence over number of stars)
  -dist STAR_DISTRIBUTION
                        Star distribution ([plummer]/king/fractal)
  -gasdist GAS_DISTRIBUTION
                        Gas distribution ([none]/plummer/king/fractal) NOT
                        IMPLEMENTED YET
  -imf INITIAL_MASS_FUNCTION
                        IMF ([kroupa]/salpeter/fixed)
  -modelnr CLUSTER_MODEL_NUMBER
                        Model number
  -kingw KING_PARAMETER_W0
                        King W0 parameter [7.0]
  -fractald FRACTAL_PARAMETER_FD
                        Fractal distribution [2.0]
  -uml UPPER_MASS_LIMIT
                        Upper mass limit (in MSun) [125.]
  -Z METALLICITY        Metallicity [0.01]
  -ibf INITIAL_BINARY_FRACTION
                        Initial binary fraction (0-1) [0.] NOT IMPLEMENTED YET
  -R EFFECTIVE_RADIUS   Cluster radius [3.0] (parsec)
  -vr VIRIAL_RATIO      Virial ration [0.5], 0.5=stable, 0.75=just expelled
                        gas, 0.1=collapsing

COPYRIGHT/LICENSE

See LICENSE