Plot of examples of Hα profiles from pixels containing the fan jet (black) and the fit using the BCM including (red) and excluding (blue) the two outermost wavelength points. Top: fitted profile with a low χ², showing good agreement between the blue and red curves. Bottom: profile with asymmetrical far wings that caused a high χ² value in the original fit, and a much better fit to the main component shown by the blue curve.