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Bugs/Features in the ASCA data analysis software


Last updated on 2001 Feb 17

This list is appropriate for HEAsoft v5.0/5.0.1 and supersedes the ASCA bug list for ftools v4.2 Please also check known FTOOLS bugs and A list of known XSPEC bugs.


  • ascaarf

    • We have recently found a bug in the convolution routine used in the release versions (inc. HEAsoft v5.0.1) of ascaarf. Ascaarf expands the GIS WMAPs to facilitate the PSF convolution using FFT. Usually, the expanded WMAP is square (e.g. 64x64), but in some cases it is not (e.g., 64x128) in which case the convolution routine gives a normalization which is too small by a factor of 2, and the source flux measured with such an ARF is too large by a factor of 2.

      Users can check if this is the case by looking at the screen output or the HISTORY keywords in the FITS header of the ARF files:

      HISTORY    Input WMAP array has size   44 by   43 bins
      HISTORY                  expanded to  128 by   64 bins
      
      If the two numbers on the 'expanded to' line differ, then this bug is affecting your results.

    • There is also an error in the normalization of the ARF when using the raytrace option with SIS data. The resulting ARF should be multiplied by 0.746.


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This file was last modified on Thursday, 09-Aug-2001 14:04:32 EDT

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