2011-03-17 T. Tamura
2011-03-21 Y.Terada
Mr. Yang Huan (Univ. of Science and Technology of China)
After the standard reprocess pipeline, the exposure time of XIS clean
events is about 106 ks, while that of HXD(PIN&GSO) clean events is
only about 6ks. The clean events of PIN have only about 3000 counts in
a 100ks observation!
Why most of the HXD events have been filtered while the XIS events
seem to be ok?
I check the filtering GTI files, and the cause may be HXD telemetry
saturation. If this is true, then what causes the telemetry
saturation?
Y.Terada (HXD team) and N.Yamasaki, M.Ishida (Operation team)
- Technical Answers
The small number of the exposure of the HXD
of OBSID = 704016010 is caused by the telemetry
saturation of the data acquisition system on-board
the spacecraft. During this observation, the
electrical noises of PIN diodes are tentatively
high around the lower energy channels and thus
most of the telemetry is occupied by such noise
events.
- Political notes
As described in the Technical description of
Suzaku (see the reference below), an exposure of
an observation as a point of view of the data rights
for PIs is calculated only by the XIS, and the PI
of the observation of OBSID = 704016010 agreed on
the above situation, thus this observation was
completed. No additional observations were performed.
- (ref) Technical description, Section 4.4
Note that this will be judged based on the good time intervals of the cleaned XIS event files after the standard screening. Dead times (including those due to the use of the burst option) are not taken into account. Also, the standard screening for the HXD is more strict, so the effective exposure for the HXD is of ten smaller than that of the XIS by 20% or more. Additional observations will be scheduled automatically for those non-time-critical targets the observations of which are considered incomplete by the project scientist at ISAS. In the case of time-critical observations which are incomplete or unusable, it will be the PI's responsibility to determine the best course of action.
2011-03-17 Accepted
2011-03-17 Resolved, HXD team
2011-03-22 Circulated to the Suzaku operation for policy
2011-03-22 Resolved, Suzaku team
2011-03-25 Answer to GO
2011-03-26 Closed
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Question ID = 0140