Description

This recipe produces a coadded, sky-subtracted, wavelength-calibrated, datacube from a group of sky-object pairs of IFU frames. The telescope offsets are used to mosaic datacubes together, allowing a region larger than the field of view of the IFU to be mapped.

Read-noise and Poisson variances are added to the frame and a bad pixel mask is applied. The spectrum from each slice of the IFU is cut out of the frame and pasted in a new frame in such a way that there are no longer spaces between the spectra, the spectra are arranged in the order in which they appear in the field of view and they are approximately aligned in the dispersion direction. The spectrum is flat-fielded and the wavelength calibration measured from the arc spectrum is used to apply a common, linear wavelength scale to each row of the 2-d spectrum.

Sky-object pairs are now subtracted, and the resulting frame is rearranged to form a data-cube, which is mosaicked into the group.