# SkyRectangularAperture¶

class photutils.aperture.SkyRectangularAperture(positions, w, h, theta=<Quantity 0. deg>)[source]

A rectangular 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.

wscalar Quantity

The full width of the rectangle, either in angular or pixel units. For theta=0 the width side is along the North-South axis.

hscalar Quantity

The full height of the rectangle, either in angular or pixel units. For theta=0 the height side is along the East-West axis.

thetascalar Quantity, optional

The position angle (in angular units) of the rectangle “width” side. For a right-handed world coordinate system, the position angle increases counterclockwise from North (PA=0). The default is 0 degrees.

Examples

>>> from astropy.coordinates import SkyCoord
>>> import astropy.units as u
>>> from photutils import SkyRectangularAperture
>>> positions = SkyCoord(ra=[10., 20.], dec=[30., 40.], unit='deg')
>>> aper = SkyRectangularAperture(positions, 1.0*u.arcsec, 0.5*u.arcsec)


Attributes Summary

 h Check that value is either an angular or a pixel scalar Quantity. positions Check that value is a SkyCoord. theta Check that value is either an angular scalar Quantity. w Check that value is either an angular or a pixel scalar Quantity.

Methods Summary

 to_pixel(wcs) Convert the aperture to a RectangularAperture object defined in pixel coordinates.

Attributes Documentation

h

Check that value is either an angular or a pixel scalar Quantity.

positions

Check that value is a SkyCoord.

theta

Check that value is either an angular scalar Quantity.

w

Check that value is either an angular or a pixel scalar Quantity.

Methods Documentation

to_pixel(wcs)[source]

Convert the aperture to a RectangularAperture 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
aperture

A RectangularAperture object.