TiltedDisk Coordinate Frame

The TiltedDisk class is an astropy coordinate frame that describes the tilted elliptical disk structure of Liszt & Burton (1982) as modified in Krishnarao, Benjamin, & Haffner (2019). Coordinate transformations can be done easily using the standard astropy.coordinates methods and the class is compatible with the astropy.coordinates.SkyCoord object:

from modspectra.cube import TiltedDisk
from astropy.coordinates import SkyCoord
import astropy.units as u

By default, TiltedDisk assumes the tilt angles used in Krishnarao, Benjamin, & Haffner (2019), but these can be manually set as well:

c = SkyCoord(x = 1.5*u.kpc, y = .3 * u.kpc, z = -.5 *u.kpc,
             frame = TiltedDisk(alpha = 13.5*u.deg,
                                beta = 20*u.deg,
                                theta = 48.5*u.deg),
             galcen_distance = 8.127*u.kpc)

c_gal = c.transform_to('galactic')

print(c_gal)
<SkyCoord (Galactic): (l, b, distance) in (deg, deg, kpc)
    ( 354.48642214,  1.01834443,  9.48797151)>