fits_cut

astrocut.fits_cut(input_files, coordinates, cutout_size, correct_wcs=False, drop_after=None, single_outfile=True, cutout_prefix='cutout', output_dir='.', verbose=False)[source]

Takes one or more fits files with the same WCS/pointing, makes the same cutout in each file, and returns the result either in a single fitsfile with one cutout per extension or in individual fits files.

Note: No checking is done on either the WCS pointing or pixel scale. If images don’t line up the cutouts will also not line up.

Parameters
input_fileslist

List of fits image files to cutout from. The image is assumed to be in the first extension.

coordinatesstr or SkyCoord object

The position around which to cutout. It may be specified as a string (“ra dec” in degrees) or as the appropriate SkyCoord object.

cutout_sizeint, array-like, Quantity

The size of the cutout array. If cutout_size is a scalar number or a scalar Quantity, then a square cutout of cutout_size will be created. If cutout_size has two elements, they should be in (ny, nx) order. Scalar numbers in cutout_size are assumed to be in units of pixels. Quantity objects must be in pixel or angular units.

correct_wcsbool

Default False. If true a new WCS will be created for the cutout that is tangent projected and does not include distortions.

drop_afterstr or None

Default None. When creating the header for the cutout (and crucially, before building the WCS object) drop all header keywords starting with the one given. This is useful particularly for drizzle files that contain a multitude of extranious keywords and sometimes leftover WCS keywords that astropy will try to parse even thought they should be ignored.

single_outfilebool

Default True. If true return all cutouts in a single fits file with one cutout per extension, if False return cutouts in individual fits files. If returing a single file the filename will have the form: <cutout_prefix>_<ra>_<dec>_<size x>_<size y>.fits. If returning multiple files each will be named: <original filemame base>_<ra>_<dec>_<size x>_<size y>.fits.

cutout_prefixstr

Default value “cutout”. Only used if single_outfile is True. A prefix to prepend to the cutout filename.

output_dirstr

Defaul value ‘.’. The directory to save the cutout file(s) to.

verbosebool

Default False. If true intermediate information is printed.

Returns
responsestr or list

If single_outfile is True returns the single output filepath. Otherwise returns a list of all the output filepaths.