General orbit class representing an orbit
NAME:
__init__
PURPOSE:
Initialize an Orbit instance
INPUT:
- vxvv - initial conditions
3D can be either
- in Galactocentric cylindrical coordinates [R,vR,vT(,z,vz,phi)]
- [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)
- [ra,dec,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]
- (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)
- [l,b,d,U,V,W] in [deg,deg,kpc,km/s,km/s,kms]
- 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)