Subject: JEM-X Monday Meeting 2006-04-19

Participants: NL, CBJ, JC, CAO, SB, NJW.

JEM-X status (CBJ, SB): As usual, no hotspots.

GTI limits (Sco X-1 problem): There has been an email discussion
     on the possibilities to avoid the BTIs stemming from high real
     X-ray photons count rates giving high hardware trigger rates
     as it happens e.g. during Sco X-1 observations.
     Actions: Get list of science windows (examples in revolutions
     417 and 420) where this happens and
     test the procedure to override the automatically defined
     GTIs (user defined GTIs). This would be a task for JC when
     visiting ISDC at the end of this month.
     When the hardware trigger rate and the rate of accepted events
     track each other then the data are assumed to be OK - one has
     to include a correction for the grey filter value. Only in the
     case where the two countrates deviate (hardware trigger rate
     increases and accepted event rate does not) the data may be
     considered as bad (too high background). Can we define an
     algorithm that handles this? SB will look into it.
     Can we run the Sco X-1 data with the GTI limit set very high
     (in reality disabled) and check the data quality?

     Sideremark: Find examples to see if the presence of Sco X-1
     close to the axis suppresses the gain (as observed with high
     background rates).

     We miss a table of why data were rejected as a result of the
     pipeline. Could there be an executive summary with basic
     HK parameters revolution by revolution? It would be a possibility
     to do this in the same way as CAO does it for the gain history
     and put the result on the web.

     SB showed a good correlation between the JEM-X HW trigger rate
     and RADMON3 during the mission (one revolution per point).

Recent revolutions (CAO): In revolution 425 and 426 there has been a
     small set of large glitches pairwise very close in time but seem
     independent. FRSS source #4 is rather weak and the new software
     where several spectra are bundled together will be very helpful.

SDAST meeting results and OSA6 planning (NL): Speed up j_src_properties
     development.

SPIE paper (CBJ): Has worked on source position accuracy. Will show
     detector background without DXB.

AO5 preparations (NL): October 2006 release of proposal for key
     programmes with response 2006-11-17. The core program will be
     defined afterwards.

/NJW

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Niels J. Westergaard
Danish National Space Center
Juliane Maries Vej 30, DK 2100 Copenhagen O
Phone: +45 35325705; FAX:  +45 35362475