Source code for astropy.coordinates.builtin_frames.supergalactic
# -*- coding: utf-8 -*-
# Licensed under a 3-clause BSD style license - see LICENSE.rst
from astropy import units as u
from astropy.utils.decorators import format_doc
from astropy.coordinates import representation as r
from astropy.coordinates.baseframe import BaseCoordinateFrame, RepresentationMapping, base_doc
from .galactic import Galactic
__all__ = ['Supergalactic']
doc_components = """
sgl : `Angle`, optional, must be keyword
The supergalactic longitude for this object (``sgb`` must also be given and
``representation`` must be None).
sgb : `Angle`, optional, must be keyword
The supergalactic latitude for this object (``sgl`` must also be given and
``representation`` must be None).
distance : `~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_sgl_cossgb : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Right Ascension for this object (``pm_sgb`` must
also be given).
pm_sgb : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_sgl_cossgb`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
[docs]@format_doc(base_doc, components=doc_components, footer="")
class Supergalactic(BaseCoordinateFrame):
"""
Supergalactic Coordinates
(see Lahav et al. 2000, <http://adsabs.harvard.edu/abs/2000MNRAS.312..166L>,
and references therein).
"""
frame_specific_representation_info = {
r.SphericalRepresentation: [
RepresentationMapping('lon', 'sgl'),
RepresentationMapping('lat', 'sgb')
],
r.CartesianRepresentation: [
RepresentationMapping('x', 'sgx'),
RepresentationMapping('y', 'sgy'),
RepresentationMapping('z', 'sgz')
],
r.CartesianDifferential: [
RepresentationMapping('d_x', 'v_x', u.km/u.s),
RepresentationMapping('d_y', 'v_y', u.km/u.s),
RepresentationMapping('d_z', 'v_z', u.km/u.s)
],
}
default_representation = r.SphericalRepresentation
default_differential = r.SphericalCosLatDifferential
# North supergalactic pole in Galactic coordinates.
# Needed for transformations to/from Galactic coordinates.
_nsgp_gal = Galactic(l=47.37*u.degree, b=+6.32*u.degree)