yt.data_objects.derived_quantities.SpinParameter

class yt.data_objects.derived_quantities.SpinParameter(data_source)[source]

Calculates the dimensionless spin parameter.

Given by Equation 3 of Peebles (1971, A&A, 11, 377), the spin parameter is defined as

lambda = (L * |E|^(1/2)) / (G * M^5/2),

where L is the total angular momentum, E is the total energy (kinetic and potential), G is the gravitational constant, and M is the total mass.

Parameters:

use_gas : bool

Flag to include gas in the calculation. Gas is ignored if not present. Default: True

use_particles : bool

Flag to include particles in the calculation. Particles are ignored if not present. Default: True

Examples

>>> ds = load("IsolatedGalaxy/galaxy0030/galaxy0030")
>>> ad = ds.all_data()
>>> print ad.quantities.center_of_mass()

Attributes

Methods