GalacticCoordinates

class sofia_redux.scan.coordinate_systems.galactic_coordinates.GalacticCoordinates(coordinates=None, unit='degree', copy=True)

Bases: CelestialCoordinates

Initialize galactic coordinates.

Galactic coordinates use spherical coordinates in a celestial coordinate system with the Sun at the center with the primary direction aligned to the approximate center of the Milky Way with the fundamental plane parallel to an approximation of the galactic plane slightly offset to the north. Coordinates are positive toward the north and east in the fundamental plane.

The galactic longitude is the angular distance of an object eastward along the galactic equator from the galactic center. The galactic latitude is the angle of an object northward of the galactic equator as viewed from Earth.

Parameters:

coordinateslist or tuple or array-like or units.Quantity, optional

The coordinates used to populate the object during initialization. The first (0) value or index should represent longitudinal coordinates, and the second should represent latitude.

unitunits.Unit or str, optional

The angular unit for the spherical coordinates. The default is ‘degree’.

copybool, optional

Whether to explicitly perform a copy operation on the input coordinates when storing them into these coordinates. Note that it is extremely unlikely for the original coordinates to be passed in as a reference due to the significant checks performed on them.

Attributes Summary

equatorial_pole	Return an equatorial pole.
fits_latitude_stem	Return the string prefix for latitude (DEC).
fits_longitude_stem	Return the string prefix for longitude (RA).
two_letter_code	Return the two-letter code for the coordinate system.

Methods Summary

edit_header(header, key_stem[, alt])	Edit the header with galactic coordinate information.
get_equatorial_pole()	Return the equatorial pole.
get_zero_longitude()	Return the zero longitude value.
setup_coordinate_system()	Setup the system for the coordinates.

Attributes Documentation

equatorial_pole

Return an equatorial pole.

Returns:

poleEquatorialCoordinates

fits_latitude_stem

Return the string prefix for latitude (DEC).

Returns:

str

fits_longitude_stem

Return the string prefix for longitude (RA).

Returns:

str

two_letter_code

Return the two-letter code for the coordinate system.

Returns:

str

Methods Documentation

edit_header(header, key_stem, alt='')

Edit the header with galactic coordinate information.

Parameters:

headerastropy.io.fits.header.Header

The header to modify.

key_stemstr

The name of the header key to update.

altstr, optional

The alternative coordinate system.

Returns:

None

classmethod get_equatorial_pole()

Return the equatorial pole.

Returns:

poleEquatorialCoordinates

classmethod get_zero_longitude()

Return the zero longitude value.

Returns:

astropy.units.Quantity

setup_coordinate_system()

Setup the system for the coordinates.

Returns:

None