galpy.orbit.Orbit

class galpy.orbit.Orbit(vxvv=None, uvw=False, lb=False, radec=False, vo=235.0, ro=8.5, zo=0.025, solarmotion='hogg')

General orbit class representing an orbit

__init__(vxvv=None, uvw=False, lb=False, radec=False, vo=235.0, ro=8.5, zo=0.025, solarmotion='hogg')

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)]
2. [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)
3. [ra,dec,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]
4. (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)
5. [l,b,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]

4. and 5) also work when leaving out b and mu_b/W

OPTIONAL INPUTS:

radec - if True, input is 2) (or 3) above

uvw - if True, velocities are UVW

lb - if True, input is 4) or 5) above

vo - circular velocity at ro

ro - distance from vantage point to GC (kpc)

zo - offset toward the NGP of the Sun wrt the plane (kpc)

solarmotion - ‘hogg’ or ‘dehnen’, or ‘schoenrich’, or value in [-U,V,W]

OUTPUT:

instance

HISTORY:

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