|STIS Instrument Handbook for Cycle 25|
The FP-SPLIT slits consist of two sets of five slits–in each set the slits are all the same size. They are for use with the MAMA echelle gratings. It is possible to achieve high S/N data for bright targets, independently of the quality of the flat-field, by means of a special observing strategy wherein multiple spectrograms are obtained through these slits.
Figure 13.78: Schematic of the STIS Fixed-Pattern Slit Configuration. AXIS1 corresponds to the dispersion direction, and AXIS2 to the spatial direction. Dimensions are not to scale.
Table 13.30: 0.2X0.2FP(A-E) Slit Throughputs