eta_function¶
- clustertools.analysis.functions.eta_function(cluster, mmin=None, mmax=None, nmass=10, rmin=None, rmax=None, vmin=None, vmax=None, emin=None, emax=None, kwmin=0, kwmax=1, npop=None, indx=None, projected=False, plot=False, meq=False, **kwargs)[source]¶
NAME: Find power slope of velocity dispersion versus mass
mass bins are set up so that there are an equal number of stars in each bin
- Parameters:
- clusterclass
StarCluster instance
- mmin/mmaxfloat
specific mass range
- nmass
number of mass bins used to calculate alpha
- rmin/rmax
specific radial range
- vmin/vmaxfloat
specific velocity range
- emin/emaxfloat
specific energy range
- kwmin/kwmaxint
specific stellar evolution type range
- npopint
population number
- indxbool
specific subset of stars
- projectedbool
use projected values (default: False)
- plotbool
plot the mass function
- Returns:
- m_meanfloat
mean mass in each bin
- sigvmfloat
velocity dispersion of stars in each bin
- etafloat
power-law slope of (sigvm ~ m^eta)
- eetafloat
error in eta
- yetafloat
y-intercept of fit to log(sigvm) vs log(m)
- eetafloat
error in yeta
- Other Parameters:
- kwargsstr
key words for plotting