calibrate_wavelength

ndmapper.lib.gmos.spec.ifu.calibrate_wavelength(*args, **kwargs)

Determine an absolute wavelength solution for each row (fibre) of the input spectra. Currently, this information is saved only in an IRAF database, whence it is picked up directly by the rectification step.

In future, this will be replaced by two Python steps that use AstroPy gWCS to propagate a two-component wavelength solution, one mapping the differences between fibres and the other a reference spectrum from pixels to wavelength units.

Parameters:

inputs : DataFileList or DataFile

Input images with extracted, row-stacked spectra, from which to determine a wavelength fit by comparision with the line_list.

order : int, optional

Order of the one-dimensional Chebyshev fitting function, used to describe wavelength as a function of pixel index for each row (default 4).

line_list : str, optional

Name of a text file from which reference wavelengths are to be read for the spectral lines present in the source spectrum (see the help for IRAF task “identify”). The default is “gmos$data/CuAr_GMOS.dat”.

interact : bool, None

Inspect & modify the line identifications and fitting functions interactively in IRAF? If None (default), interactivity is instead controlled by the package configuration dictionary (see below).

See “help gswavelength” in IRAF for more detailed information.

Returns:

DataFileList

The (unmodified) inputs, with newly-associated wavelength solution databases in IRAF.