NFW potential¶
- class galpy.potential.NFWPotential(amp=1.0, a=1.0, normalize=False, rmax=None, vmax=None, conc=None, mvir=None, vo=None, ro=None, H=70.0, Om=0.3, overdens=200.0, wrtcrit=False)[source]¶
Class that implements the NFW potential
\[\rho(r) = \frac{\mathrm{amp}}{4\,\pi\,a^3}\,\frac{1}{(r/a)\,(1+r/a)^{2}}\]- __init__(amp=1.0, a=1.0, normalize=False, rmax=None, vmax=None, conc=None, mvir=None, vo=None, ro=None, H=70.0, Om=0.3, overdens=200.0, wrtcrit=False)[source]¶
NAME:
__init__
PURPOSE:
Initialize a NFW potential
INPUT:
amp - amplitude to be applied to the potential (default: 1); can be a Quantity with units of mass or Gxmass
a - scale radius (can be Quantity)
normalize - if True, normalize such that vc(1.,0.)=1., or, if given as a number, such that the force is this fraction of the force necessary to make vc(1.,0.)=1.
Alternatively, NFW potentials can be initialized in the following two manners:
rmax= radius where the rotation curve peaks (can be a Quantity, otherwise assumed to be in internal units)
vmax= maximum circular velocity (can be a Quantity, otherwise assumed to be in internal units)
conc= concentration
mvir= virial mass in 10^12 Msolar
in which case you also need to supply the following keywords
H= (default: 70) Hubble constant in km/s/Mpc
Om= (default: 0.3) Omega matter
overdens= (200) overdensity which defines the virial radius
wrtcrit= (False) if True, the overdensity is wrt the critical density rather than the mean matter density
ro=, vo= distance and velocity scales for translation into internal units (default from configuration file)
OUTPUT:
(none)
HISTORY:
2010-07-09 - Written - Bovy (NYU)
2014-04-03 - Initialization w/ concentration and mass - Bovy (IAS)
2020-04-29 - Initialization w/ rmax and vmax - Bovy (UofT)