galpy.orbit.Orbit

class galpy.orbit.Orbit(vxvv=None, uvw=False, lb=False, radec=False, vo=None, ro=None, zo=None, solarmotion=None)

General orbit class representing an orbit

__init__(vxvv=None, uvw=False, lb=False, radec=False, vo=None, ro=None, zo=None, solarmotion=None)

NAME:

__init__

PURPOSE:

Initialize an Orbit instance

INPUT:

vxvv - initial conditions
3D can be either
  1. in Galactocentric cylindrical coordinates [R,vR,vT(,z,vz,phi)]; can be Quantities
  2. astropy (>v3.0) SkyCoord that includes velocities (Note that this turns on physical output even if ro and vo are not given)
  3. [ra,dec,d,mu_ra, mu_dec,vlos] in [deg,deg,kpc,mas/yr,mas/yr,km/s] (all J2000.0; mu_ra = mu_ra * cos dec); can be Quantities; ICRS frame
  4. [ra,dec,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]; can be Quantities; ICRS frame
  5. (l,b,d,mu_l, mu_b, vlos) in [deg,deg,kpc,mas/yr,mas/yr,km/s) (all J2000.0; mu_l = mu_l * cos b); can be Quantities
  6. [l,b,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]; can be Quantities
  7. Unspecified: assumed to be the Sun (equivalent to vxvv= [0,0,0,0,0,0] and radec=True)
  1. and 6) also work when leaving out b and mu_b/W

OPTIONAL INPUTS:

radec= if True, input is 2) (or 3) above (Note that this turns on physical output even if ro and vo are not given)

uvw= if True, velocities are UVW

lb= if True, input is 4) or 5) above (Note that this turns on physical output even if ro and vo are not given)

ro= distance from vantage point to GC (kpc; can be Quantity)

vo= circular velocity at ro (km/s; can be Quantity)

zo= offset toward the NGP of the Sun wrt the plane (kpc; can be Quantity; default = 25 pc)

solarmotion= ‘hogg’ or ‘dehnen’, or ‘schoenrich’, or value in [-U,V,W]; can be Quantity

If ro and/or vo are specified, outputs involving distances or velocities (whether as instance methods or in plots) will by default be displayed in the physical coordinates implied by these scales. This can be overwritten for each individual method by using use_physical=False as a keyword for the method.

OUTPUT:

instance

HISTORY:

2010-07-20 - Written - Bovy (NYU)