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7.14 Removal of the grating spectral element

 

Due to the uncertainty in the grating setting, and the fact that the processing software assumes that the grating is set to the commanded position (it only has information on the commanded position), the removal of the grating spectral element from FP data (see section 6.4.6) can introduce artificial slopes in the spectrum. This is especially true for grating positions far from the rest position (about equal to the center wavelength of the detector band). This means that continuum flux and spectral shape of an FP spectrum need not necessarily reflect the true source flux and spectral shape. In general it is not recommended to use the FP spectra to determine continuum shapes and fluxes.



N.Trams, ISO Science Operations Team
Using inputs from:
C.Gry, T. Lim, LWS Instrument Dedicated Team
A.Harwood, P.E.Clegg, B.Swinyard, K.King, LWS Instrument Team
S.Lord, S.Unger, IPAC.