Subject: JEM-X Monday Meeting 2005-08-01

After a long summerbreak without minutes of the JEM-X regular
Monday Meetings the reporting is resumed from today.

Present: NL, SB, CAO, NJW

Status for JEM-X instruments (SB):
    Middle of July: Loss of one revolution of data due to high radiation level
    Since July 28, morning: JMX1 in SAFE mode due to high radiation level
    DPE crash occurred saturday, recovered by power cycling. Complete
    reconfiguration done. We will get report later.

SVR status (NJW): New sections: imaging with j_ima_iros, mosaicking with
    j_ima_mosaic. Source detection sensitivity.
    Still needing updates: spectral/lightcurve extraction. New figures
    with OSA5 software are requested. Weak source analysis and pulsar
    analysis is be renewed.
    
New spectrum extraction (NL): Postponed to a later, dedicated, meeting.
    With the new focus on detection efficiency as a function of local,
    current gain values we need to design the tool very carefully.

Crab positions from j_ima_iros (NJW,NL): The positions given in SRCL-RES
    for Crab observations deviated by 20 arcsec from the catalog value.
    On the other hand, close inspections of the images from j_ima_iros
    shows no similar offset. Could it be due to extra corrections by
    CRPIXi, CRVALi or the centroiding algorithm? Action on NL.

New j_cor_gain (CAO): A new version of j_cor_gain has been made. This
    version gives an improved gain correction i.e. fewer pathologic
    cases.
    It was discussed whether it would be a good idea to produce standard
    file(s) with the gain correction coefficients once established
    in the style of IC files. The algorithm of j_cor_gain could then
    ask for the presence of such data and use them if found or generate
    a new fit if not found.
    In any case CAO proposes to make a web page with such gain correction
    information for the general user to consult to check the quality of
    the correction or for good advice in case of problems.
    
Gain maps based on the Xe line (SB): It is possible to make adequate
    mapping of the Xe line in 32 x 32 rebinned detector maps if 10
    revolutions are combined.
    Preliminary results show that the gain does not evolve uniformly
    across the detector surface.
    
SgrA* analysis (NL): Data is well spread in time and ownership. A new
    effort will be done to collect as much as possible and resume the
    quest for the elusive source.

Coming Crab calibration: It it coming at all? SB wants to make an exercise
    with lowered HV to decrease the gain in order to map the detection
    efficiency at low gain. This does not require the Crab in the FOV.
    But for many other reasons Crab observations will be very useful.
    For the moment we have no particular requests for pointing directions
    except the obvious ones.

Next SDAST meeting (CAO): The next SDAST meeting has been loosely planned
    at the very beginning of September (in Copenhagen). CAO would like
    to change the time with a few days. We should make a call for a new
    date and/or acceptance.

/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