Full Spectrum

The prime observations (listed in Table 3.1) consist of complete coverage of the wavelength range 47-196.9 $\mu$m. The reduced observations are shown individually in Appendix D and plotted together in Figure 4.1. This figure shows a fit to the grating observation (described in Section 3.1.3) for comparison. Each observation was binned with a width equal to 1 resolution element and no extra scaling factors were applied to the flux levels. For wavelengths below 104 $\mu$m (detectors SW1-LW1), the absolute flux level agrees very well between the FP and grating observations but above 104 $\mu$m there are large discrepancies. This is particularly true for detectors LW2 (104-131 $\mu$m) and LW3 (131-153 $\mu$m) which both have higher flux levels than the grating. However, the absolute flux from the grating is highly uncertain in this range due to the non-linearities in detector response that were described in Section 3.1.3 and it is very difficult to determine the true shape of the spectrum. The curved shape across the wavelength range of these two detectors in the FP data indicates that the RSRF may not have been completely removed. The simplest way for this to have occurred would be via an offset in the dark current but this cannot be the full explanation because a large unphysical change in the dark value would be needed to remove the curvature. The coverage of non-prime data using FPS in this range was not high enough to conclusively determine if the effect was specific to FPL.