THE FINAL ARCHIVE AND RECALIBRATION OF THE INTERNATIONAL ULTRAVIOLET EXPLORER (IUE) SATELLITE

Since 1978 the International Ultraviolet Explorer (IUE) satellite has been acquiring the largest collection of astronomical ultraviolet spec tra that will likely be obtained in the foreseeable future. The more t han 100 000 spectral images, from which low and high dispersion spectr a are extracted, include a very broad range of sources from solar syst em objects, stars of all types, interstellar and Galactic halo gas, no rmal galaxies, and active galactic nuclei. The Final Archive of IUE da ta will contain all of these spectral images and extracted spectra, re processed with uniform software and calibrations that enhance the qual ity of the data products. This paper summarizes the rationale for and content of the new processing algorithms, together with the calibratio n chronology of the IUE scientific instrument. Examples of spectra pro cessed for the Final Archive demonstrate an increased signal-to-noise ratio of 10%-50% for low dispersion data and similar to 100% or more f or high dispersion data compared to the old processing scheme, the ext ension of the usable spectral range down to 1150 and up to 3400 Angstr om, and the emergence of new spectral features from the fixed pattern noise that is now largely eliminated. (C) 1996 American Astronomical S ociety.