SkyCircularAnnulus

class photutils.aperture.SkyCircularAnnulus(positions, r_in, r_out)

Bases: SkyAperture

A circular annulus aperture defined in sky coordinates.

The aperture has a single fixed size/shape, but it can have multiple positions (see the positions input).

Parameters:

positionsSkyCoord

The celestial coordinates of the aperture center(s). This can be either scalar coordinates or an array of coordinates.

r_inscalar Quantity

The inner radius of the circular annulus in angular units.

r_outscalar Quantity

The outer radius of the circular annulus in angular units.

Examples

>>> from astropy.coordinates import SkyCoord
>>> import astropy.units as u
>>> from photutils.aperture import SkyCircularAnnulus
>>> positions = SkyCoord(ra=[10.0, 20.0], dec=[30.0, 40.0], unit='deg')
>>> aper = SkyCircularAnnulus(positions, 0.5*u.arcsec, 1.0*u.arcsec)

Attributes Summary

isscalar	Whether the instance is scalar (i.e., a single position).
positions	The center position(s) in sky coordinates.
r_in	The inner radius in angular units.
r_out	The outer radius in angular units.
shape	The shape of the instance.

Methods Summary

copy()	Make an deep copy of this object.
to_pixel(wcs)	Convert the aperture to a CircularAnnulus object defined in pixel coordinates.

Attributes Documentation

isscalar

Whether the instance is scalar (i.e., a single position).

positions

The center position(s) in sky coordinates.

r_in

The inner radius in angular units.

r_out

The outer radius in angular units.

shape

The shape of the instance.

Methods Documentation

copy()

Make an deep copy of this object.

Returns:

resultAperture

A deep copy of the Aperture object.

to_pixel(wcs)

Convert the aperture to a CircularAnnulus object defined in pixel coordinates.

Parameters:

wcsWCS object

A world coordinate system (WCS) transformation that supports the astropy shared interface for WCS (e.g., astropy.wcs.WCS, gwcs.wcs.WCS).

Returns:

apertureCircularAnnulus object

A CircularAnnulus object.