Sky flat datacube is the name of the wavelength calibrated sky flat datacube, which should be displayed as Wavelength calib sky flat datacube . It is used if you check the left button. Same input possibilities as above. Same input possibilities as above. Five to seven is usually OK, with the fit going nicely through the noise.
Greater values increase the level of smoothing.
Note that non-integer values are allowed. They can be recalled at will, and are used each time the Compute flat field table window is opened. The low-frequency flat field correction computed during the preceding step is applied to the wavelength calibrated object datacube, and a new datacube is created, holding the wavelength calibrated and flat fielded spectra of the object. This new file appears as Flat fielded object datacube in the reduction folder display. Use Click on Flat , in the main menu, then on Apply flat field .