MAP_CONTINUUM GLOBAL

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MAP_CONTINUUM GLOBAL

            [ADVANCED\]MAP_CONTINUUM [DIRTY|CLEAN|Other] /METHOD GLOBAL [Thresh-
        old [Nhisto]]

          Compute  the  integrated spectrum (over the region specified by CENTER
        and SIZE variables), and delineate the line-free region by Gaussian fit-
        ting the histogram of the spectrum intensity.
          The  optional  arguments  control the algorithm. Threshold is clipping
        level in sigma units: values in range 2.5 - 5 are usable (default  3.5).
        Nhisto  is  the  number of histogram bins. The default is to adjust this
        number depending on the number of channels in the data. This is the same
        algorithm  as  used in UV_CONTINUUM, or in a per pixel mode by the GAUSS
        method.

          The continuum is then derived by integrating in the line-free regions.
        This  method  is fast, and gives a uniform noise since the same channels
        are used for all pixels.  It may be inaccurate into several ways:
        - Regions with strong broad line may still be contaminated  by  emission
        from the line wings
        - The same applies to regions with line confusion.
        -  Continuum emission in regions with no line emission is not derived to
        the maximum sensitivity. This can be an issue in case of line  confusion
        at some positions.