galpy.potential.LinShuReductionFactor¶

galpy.potential.LinShuReductionFactor(axiPot, R, sigmar, nonaxiPot=None, k=None, m=None, OmegaP=None)[source]¶

Calculate the Lin & Shu (1966) reduction factor: the reduced linear response of a kinematically-warm stellar disk to a perturbation

Parameters:

axiPot (Potential or list of Potential instances) – The background, axisymmetric potential
R (float or Quantity) – Cylindrical radius
sigmar (float or Quantity) – Radial velocity dispersion of the population
nonaxiPot (Potential object, optional) – A non-axisymmetric Potential instance (such as SteadyLogSpiralPotential) that has functions that return OmegaP, m, and wavenumber. Either provide nonaxiPot or m, k, OmegaP.
k (float or Quantity, optional) – Wavenumber (see Binney & Tremaine 2008). Either provide nonaxiPot or m, k, OmegaP.
m (int, optional) – m in the perturbation’s m x phi (number of arms for a spiral). Either provide nonaxiPot or m, k, OmegaP.
OmegaP (float or Quantity, optional) – Pattern speed. Note that in the usual Lin-Shu formula omega = m x OmegaP. Either provide nonaxiPot or m, k, OmegaP.

Returns:

The reduction factor

Return type:

float

Notes