Subject: JEMX Monday Meeting 2006-01-09

NB: from last week:

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

JEMX status: No hotspot activity right now. All is well.

User Manual Updates (NL): Corrected text for chapter 2 has been
         circulated internally, approved and handed over to PK.

Gain archive status (CAO): Revolution 276 show clear sign of gain
         depression over entire detector as derived from the Xe-line
         position. Number 218 and 318 show similar signs.
         CAO will check if background level is unusually high.
         On rare occasions only the Xe peak has shifted position
         when the Mo and Cu peaks are at usual positions. These cases
         will also be studied more closely.

         Question (CBJ): Can we have the gain factor for each revolution?
         Yes, there is a quite simple way to produce that.

Status for alignment studies (NL, CBJ): The correction of the bug for
         parallax effect has shown no significant improvement for the
         source positions in j_ima_iros.

         Revol. 239 analyzed for deriving fluxes (CBJ). The correction
         as a function of mask temperature is significant. The position
         determination was also analyzed for this revolution showing
         less than 5 arcsec deviations for the 5x5 dither (40 arcmin
         spacing) around the bore sight but for the 4 deg ring
         deviations of +-20 arcsec are seen for JMX1.

         Can we reuse the CBJ software for (parts of) j_ima_iros?

Status for spectral extraction software (NL, NJW): The first step to
         sort out the functions in j_ima_iros is still going on
         as well as a refinement of the constants used for
         source positioning and PIF determination. 

Electronic efficiency (SB): The efficiency change around PHA=115
         (where the rejection criteria set in) is sharper in raw PHA
         than in PHA (where curtain correction has been applied).
         This has been verified in an analysis of an on-axis Crab
         observation.

         More observations in diagnostic mode should be requested e.g.
         in OMC flatfielding periods.

/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