The ISOPHOT calibration group has found that the two Cal G tables PCMBBONE.FITS and PCMBBTWO.FITS which list the colour correction factors for a modified blackbody (Fnu = nu^beta * Bnu(T), where nu is the frequency, Bnu the Planck function, and, T the temperature) with emissivity proportional to nu and nu^2, respectively are incorrect.
As a result, the tables stored in Cal-G files PCCMBBONE.FITS PCCMBBTWO.FITS have been regenerated.
Consequently, the Cal G files PCCMBBONE and PCCMBBTWO which are presently available in the archive are incorrect and are superseded by the newly generated ones. Due to configuration control constraints it is not possible to update the OLP Cal-G database until the next software release.
THEREFORE, ANY RETRIEVAL OF THESE FILES FROM THE ISO DATA ARCHIVE WILL YIELD THE OLD INCORRECT VERSIONS. Instead, the new and correct versions should be retrieved via the PIA homepage.
Please note that all other OLP version 7.0 and 8.x archive products are not impacted and can continue to be used.
We will post a message as soon as IDA contains the correct PCCMBBONE and PCCMBBTWO tables.
Rene Laureijs and Ulrich Klaas,
for the ISOPHOT calibration group, 23 December 1999