Dehnen bar potential

class galpy.potential.DehnenBarPotential(amp=1.0, omegab=None, rb=None, chi=0.8, rolr=0.9, barphi=0.4363323129985824, tform=-4.0, tsteady=None, beta=0.0, alpha=0.01, Af=None)

Class that implements the Dehnen bar potential (Dehnen 2000)

__init__(amp=1.0, omegab=None, rb=None, chi=0.8, rolr=0.9, barphi=0.4363323129985824, tform=-4.0, tsteady=None, beta=0.0, alpha=0.01, Af=None)

NAME:

__init__

PURPOSE:

initialize a Dehnen bar potential

INPUT:

amp - amplitude to be applied to the potential (default: 1., see alpha or Ab below)

barphi - angle between sun-GC line and the bar’s major axis (in rad; default=25 degree)

tform - start of bar growth / bar period (default: -4)

tsteady - time at which the bar is fully grown / bar period (default: tform/2)

Either provide:

1. rolr - radius of the Outer Lindblad Resonance for a circular orbit

   chi - fraction R_bar / R_CR (corotation radius of bar)

   alpha - relative bar strength (default: 0.01)

   beta - power law index of rotation curve (to calculate OLR, etc.)

2. omegab - rotation speed of the bar

   rb - bar radius

   Af - bar strength

OUTPUT:

(none)

HISTORY:

2010-11-24 - Started - Bovy (NYU)