Subject: Energy limits for JEMX archive images

Dear all,

Since the ISDC reprocessing and archive building with additional
products such as images is to start very soon, Peter requested
input on sensible energy limits for these images. After a discussion
with Niels L. we came up with the following proposal

    <=  PI   <=       <  Energy(keV)  <
    30       57      1.8             4.0
    58      118      4.0             9.0
   119      159      9.0            15.0
   160      196     15.0            25.0
   197      235     25.0            50.0
   
Comments: The first energy band will be uncertain wrt. efficiency,
          due to the gain variations with time. It is a value for
          the detection of very soft sources. The lower PI limit
          is defined so that very few counts will have lower PI values.
          The fourth energy band has an upper limit below the Xe line.
          The last and highest interval is defined with obscured
          sources or very hard spectrum sources in mind. As with the
          first energy band the efficiciency is gain dependent.
          The middle three bands should be quite well defined.
          
If you have some thoughts why these intervals should be different from
this, then please say so very soon - this will be frozen in the beginning
of next week and it will require very good arguments to make changes halfway
in the reprocessing.

Regards

Niels Jørgen

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Niels J. Westergaard
Danish Space Research Institute
Juliane Maries Vej 30, DK 2100 Copenhagen O
Phone: +45 35 32 57 05; FAX:  +45 35 36 24 75