The calibration applied by IUESPEC is described in IUE NASA Newsletters 10, 14, 21, 23, 35, and 41, and in IUE ESA Newsletter 17. It is applied by a subroutine called CALIB which can be run interactively.
If you are working with LWR low dispersion data, you can have CALIB apply a sensitivity degradation correction by setting a flag in the H vector. This can be done with a procedure called SDC. (Note: this is not the only sensitivity degradation correction available. Read the discussion of RBSENSCOR, which is applied after CALIB.)
SDC,H (for LWR low dispersion data only; see above)
T is the exposure time in seconds. Both high and low dispersion IUESIPS spectra may be calibrated with CALIB.
Two alternative calibrations are available. These programs expect the data to have been calibrated by CALIB first, and then apply corrections. They are:
DFCORR,W,FCAL,FCOR David Finley's correction, based on white dwarf models,
RBCORR,CAM,AP,W,FCAL,FCOR Ralph Bohlin's correction.
|CAM||0 (LWP, ITF1), 1 (LWP, ITF2), 2 (LWR), or 3 (SWP)|
|AP||1 (trailed exposure), 2 (small aperture), or 3 (large aperture point source)|
In both cases, FCAL are the fluxes from CALIB, and FCOR are the corrected fluxes. NOTE: You may wish to perform other corrections before correcting the calibrations with these two programs. See Section 5.4.