Subject: Problem: hotspots in ScW Standard Analysis


   Hi,

   checking out some results of ISDC's Science Window SA which is supposed
to be archived soon, I've encountered a curious problem. Keep in mind that
this analysis was run with OSA 4.1(one!) ISSW and older IC files as the
latest software and IC files are not yet validated and there is a lot of
pressure to get science results in the public archive. The data can be
found under /isdc/pvphase/reproc/ops_sa/obs_jmx/0026.000/

   These observations are affected by a nice and strong hotspot, which in
OSA 4.1 is not perfectly taken out. Because we also instructed ISDC to
include the very low energy band channel 30-57 (1.8-4 keV), the hotspot
leads to quite significant 'new sources' in JMX2-SRCL-RES, where their
significance is mostly from this first band (j_ima_src_find reports the
_maximum_ significance in all bands). For some examples please see:

    ssj2_002600620010/scw/002600620010.001
    ssj2_002600810010/scw/002600810010.001

below the directory mentioned above.

   So what do we do now with these results that are supposed to go into
a public archive very soon? Options I see are:

* Leave data as is, but make sure the new sources are ignored for
   tables of results derived from our data.

* Ask ISDC to rerun with changed parameters (skip lowest bans) in order to
   exclude the hotspots.

* Tell ISDC (and ESA) that the public archive can only be done with OSA 4.2
   [in that case there is urgent need vor validation!!!]


   Curious,
   Peter


Hello Peter,

We discussed this on the Monday meeting and the conclusion was that
we'd better discard the lowest energy band and redefine the
next lowest energy channel so that the minimum energy is 3 keV.

It seems that the complications with the low channel outweigh the
benefits.

Is that still an option ?

Regards

Niels Jørgen



   That depends ... on the one hand we have lot of pressure on us
to have these data online. On the other hand there have been some
discussions about it and we can reprocess the full set in a few days
(2-3?). So I do not know yet how ISDC's management will decide.

   Cheers,
   Peter