This slit is supported with use of the
first-order gratings and prism and provides the best spatial and spectral resolution of the long slits. This aperture is the 2 pixel wide slit in the dispersion direction for the MAMA first-order modes.
Observations with this slit require a PEAKUP
prior to science observations. The actual width of this aperture is 34 milliarcsec instead of 50 milliarcsec, the value suggested by its name. Special pseudo-apertures have been defined to minimize detector effects such as background and CTE. See next page for more information.