Simple tools to work with the Initial Mass Function

Some basic examples below.

1. Make a simple 1000 Msun cluster sampled from the default Kroupa IMF:

   cluster = imf.make_cluster(1000)

   or from a Salpeter IMF:

   cluster = imf.make_cluster(1000, massfunc='salpeter')

2. Create a sample of clusters to do some analysis of later. This will make clusters with masses Gaussian-distributed around a given mean mass in the list of cluster_masses, so that you could then do things like estimate the typical luminosity of a cluster for a given mass:

   from imf import imf from astropy.utils.console import ProgressBar cluster_masses = [100, 1000, 10000] nclusters_per_bin = 30 clusters = np.array([[imf.make_cluster(mass*(np.random.randn()/20.+1.), silent=True) for ii in range(nclusters_per_bin)] for mass in ProgressBar(cluster_masses)])

3. Calculate the mass fraction represented by M>8 Msun stars in a Kroupa IMF when the maximum mass is 200 Msun:

   kroupa = imf.Kroupa()
   
   mmax = 200
   cutoff1 = 8
   
   over8fraction = (kroupa.m_integrate(cutoff1, mmax)[0] /
                    kroupa.m_integrate(kroupa.mmin, mmax)[0])

4. This figure was made with examples/imf_figure.py

Credits:

• Adam Ginsburg (@keflavich, wrote most of this)
• Sergey Koposov (@segasai, majorly refactored the distribution functions)
• Tiffany Christian (@teachristian, made some small corrections)
• Theo Richardson (@richardson-t, refactored optimal sampling)

No formal citation is available yet; please just reference the repository (https://github.com/keflavich/imf) if you use this.