Source code for astropy.coordinates.builtin_frames.supergalactic
# -*- coding: utf-8 -*-
# Licensed under a 3-clause BSD style license - see LICENSE.rst
from __future__ import (absolute_import, unicode_literals, division,
print_function)
from ... import units as u
from ..representation import SphericalRepresentation
from ..baseframe import BaseCoordinateFrame, RepresentationMapping
from .galactic import Galactic
[docs]class Supergalactic(BaseCoordinateFrame):
"""
Supergalactic Coordinates
(see Lahav et al. 2000, <http://adsabs.harvard.edu/abs/2000MNRAS.312..166L>,
and references therein).
Parameters
----------
representation : `BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
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.
"""
frame_specific_representation_info = {
'spherical': [RepresentationMapping('lon', 'sgl'),
RepresentationMapping('lat', 'sgb')],
'cartesian': [RepresentationMapping('x', 'sgx'),
RepresentationMapping('y', 'sgy'),
RepresentationMapping('z', 'sgz')]
}
frame_specific_representation_info['unitspherical'] = \
frame_specific_representation_info['spherical']
default_representation = SphericalRepresentation
# 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)