PIMMS Version s2.1a Release Note

This version contains these new features and updates:

• A new version of the XTE PCA effective area curve (see below for details).
• The HEAO-1 A4 LED effective area is now available, giving the ability to predict count rates in the 4 bands used by Levine et al (1984, ApJS 54, 581).
• The Spectrum-X-Gamma SODART (with LEPC, HEPC, and SIXA) effective area is now included.
• The SAX (with LECS, MECS, HPGSPC, PDS and WFC) effective area is now included.
• A number of miscellaneous bug fixes have been implemented.

The new XTE PCA effective area curve brings count rate estimates using PIMMS and the 256 channel and 6 channel PCA matrices (used in XSPEC) into agreement. Earlier versions of PIMMS used a slightly larger, but not unreasonable, PCA effective area and used a response matrix having an energy scale and offset different from the 6 channel matrix. The effect is that the total count rate was larger than that obtained using the 6 channel PCA matrix (5det_6ch.rmf) by a factor of 1.143, and that counts in the lowest canonical channel were underestimated.

This file was last modified on Wednesday, 14-May-2025 11:55:19 EDT