Important XIS events for data analysis
Updated on 2008-03-24
2009
10/12 4:00-10/14 12:10
After a diagnostic operation of XIS0, the senor failed to go back to
observation. Resultantly, XIS0 was unoperational during the period
above. Other sensors (XIS1 and 3) were in operation, but their dark
levels may be inproperly estimated until 10/14 10:30. Users are advised
not to use data during this period without a consultation to the XIS team.
7/6 10:36 - 7/7 5:27
During the observation of TT Ari, the erroneous dark frame
problem occurred in all the sensors. The event data in
RAWY < 119 were affected by this problem.
See this page for the detail of this symptom.
6/23 - 9/7, 10/12
Diagnostic operations for XIS0 were occasionally performed.
XIS0 data obtained during this period might include some frames
for diagnostic purposes, which should be removed for data
reduction by general users.
6/27 16:30
The area discrimination (RAWX=70-150) is applied for all the data
obtained from this time onward, which masks most of the fake events
due to the leak current in the XIS0 segment A.
6/23 2:00
An anomaly occurred in XIS0. A part of the XIS0 segment A
was suddenly flooded by a large amount of leak current.
This part (RAWX=70-150) became not usable any longer.
5/18 8:22 - 10:04
Temperature anomaly in XIS0.
The CCD temperature increased up to -60 degC, although the
HK data showed an incorrect value of -90 degC.
The XIS0 data in this period are not usable because
large amount of the dark current filled the telemetry
with the false events.
4/13 5:46 - 7:26
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -51 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
2/18 2:03 - 3:44
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -77 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
2008
12/6 19:12 - 20:51
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -50 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
10/27 9:55 - 11:37
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -78 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
9/18 15:43 - 9/19 2:13
Temperature anomaly in XIS3.
The CCD temperature decreased down to -93 degC, although the
HK data showed no apparent change.
No significant impact on the data, but the sensor might have
slightly different gain.
9/10 7:36 - 9:18
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -81 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
8/1 5:05 - 6:45
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -45 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
4/21 14:05 - 15:46
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -46 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
2008
2/22 11:40 - 20:30
When Suzaku started to observe IGRJ17391-3021, illegal
commands were issued to the XIS due to a mistake in operation.
This resulted in an incorrect onboard dark estimation, and the
data obtained before 2008-02-22 20:30(UT) cannot be used.
1/30 18:55 - 2/6 04:50
Trouble in the CPU board of the XIS data processing unit.
No XIS data usable for scientific purpose were produced
in this period. XIS was restarted using the backup
CPU board and resumed the observations.
2007
12/23 02:53-04:29
Temperature anomaly in XIS1.
The CCD temperature increased up to -65 degC, although the
HK data showed an incorrect value around -94 degC.
The XIS1 data in this period are not usable because
large amount of the dark current filled the telemetry
with the false events.
12/19 23:40 - 12/20 1:19
Temperature anomaly in XIS0.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -76 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
12/8 4:48 - 12/12 0:30
Trouble in the on-board data processing of XIS0.
No usable data were output for Segments C & D of XIS0.
The HK data were also invalid for these segments.
The trouble was caused by the bit-upset due to energetic
particles in SAA in one of the data processing units of XIS0.
11/5 21:08 - 22:48
Temperature anomaly in XIS0.
The CCD temperature increased up to -59 degC, although the
HK data showed an incorrect value around -116 degC.
The XIS0 data in this period are not usable due to the
large increase of the thermal noise.
10/29 7:18 - 17:56
Temperature anomaly in XIS1.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -83 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
10/8 11:24 - 13:03
Temperature anomaly in XIS0.
The CCD temperature decreased down to -94 degC, although the
HK data showed an incorrect value around -78 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
8/17 16:25 - 8/28 14:46
Temperature anomaly in XIS1.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -65 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
7/20 2:40 - 4:19
Temperature anomaly in XIS1.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -84 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
6/22 10:06 - 11:48
Temperature anomaly in XIS0.
The CCD temperature increased up to -58 degC, although the
HK data showed an incorrect value around -115 degC.
The XIS0 data in this period may have significantly different
performance in terms of the dark current, energy resolution
and the gain.
4/8 21:45 - 23:29
Temperature anomaly in XIS3.
The CCD temperature decreased down to -92 degC, although the
HK data showed an incorrect value around -52 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
4/8 6:13 - 7:53
Temperature anomaly in XIS0.
The CCD temperature increased up to -62 degC, although the
HK data showed an incorrect value around -113 degC.
The XIS0 data in this period may have significantly different
performance in terms of the dark current, energy resolution
and the gain.
3/31 23:53 - 4/1 1:02
Abnormally large number of events in XIS0 segment A possibly
due to the light-leak estimation error.
3/29 21:56 - 3/30 1:10
Abnormally large number of events in XIS0 segment D possibly
due to the light-leak estimation error.
3/5 3:12 - 13:47
Temperature anomaly in XIS3.
The CCD temperature decreased down to -93 degC, although the
HK data showed an incorrect value around -62 degC.
No significant impact on the data, but the sensor might have
slightly different gain.
2/15 18:13 - 20:42
Abnormally large number of events in some sensors/segments
possibly due to the light leak estimation error.
Errors were found in the following intervals:
XIS0, segment A: 18:13 - 20:42
XIS3, segment C: 19:19 - 20:42
XIS3, segment D: 18:52 - 20:42
1/10 18:06 - 19:48
Temperature anomaly in XIS2.
The CCD temperature decreased down to -94 degC, although the HK
data showed an incorrect value around -44 degC. No significant
impact on the data, but the sensor might have slightly
different gain.
2006
12/20 10:37
XIS telemetry allocation ratio was changed from 3:3:3:3 to 3:3:1:3
(XIS0:XIS1:XIS2:XIS3).
12/13 3:50-4:04
Increase of the XIS event rates (up to 800 cnts/8sec/segment)
possibly due to the solar flare (X3.4) occurred at 2:14.
12/6 19:20-19:30
Increase of the XIS event rates (up to 200 cnts/8sec/segment)
possible due to the solar flare (X6.5) occurred at 18:29.
12/5 15:13 - 16:54
Temperature anomaly in XIS0.
The CCD temperature increased up to -57 degC, although the HK
value indicated an incorrect temperature of -116 degC. The XIS0
data in this period may not be usable due to the significantly
different performance and the telemetry saturation.
12/5 10:25 - 10:35
XIS event rates increased up to 10^3 cnts/8s/segment probably
due to the large solar flare (X9.0) occurred at 10:18.
Similar but moderate increases of the event rates were observed
during the satellite day time on the same day.
11/22 11:03 - 11/23 2:10
A burst option was mistakenly applied to XIS0 and XIS3.
11/20 17:12 - 18:54
Temperature anomaly in XIS0.
The CCD temperature decreased down to -94 degC, although the HK
data showed an incorrect value around -64 degC. No significant
impact on the data, but the sensor might have slightly
different gain.
11/17 2:20 - 4:05
No XIS1 data due to an operation error.
11/9 1:04:15
Anomaly occurred in XIS2.
Large amount of extra charge flooded the CCD.
Hereafter, XIS2 became unusable.
11/9 1:56 - 3:37
Temperature anomaly in XIS1.
The CCD temperature increased up to -63 degC, although the HK
value indicated an incorrect temperature of -257 degC. The XIS1
data in this period may have significantly different performance
in terms of the dark current, energy resolution and the gain.
11/7 7:38 - 11/8 7:45
Temperature anomaly in XIS0.
The CCD temperature decreased down to -94 degC, although the HK
data showed an incorrect value around -52 degC. No significant
impact on the data, but the sensor might have slightly
different gain.
10/27 8:58 - 10:40
Temperature anomaly in XIS3. The CCD temperature increased
up to -54 degC, although the HK data incorrectly showed the nominal
value of -90 degC. The XIS2 data in this period may have
significantly different performance in terms of the energy
resolution and the gain.
9/21 7:41 - 9:21
Temperature anomaly in XIS0. CCD temperature decreased
down to -94 degC, although the HK data showed incorrect value
around -47 degC. No significant impact on the data,
but the sensor might have slightly different gain.
7/31 23:40 - 8/1 3:20
No data in FI sensors. FI sensors stayed in the standby mode
due to the error in the mode change sequence.
7/23 11:59 - 13:39
Temperature anomaly in XIS2. CCD temperature decreased
down to -91 degC, although the HK data showed incorrect value
around -56 degC. No significant impact on the data,
but the sensor might have slightly different gain.
6/29 5:09 - 15:49
Temperature anomaly in XIS2. CCD temperature decreased
down to -93 degC, although the HK data showed incorrect value
around -40 degC. No significant impact on the data,
but the sensor might have slightly different gain.
6/16 2:16 - 3:57
Temperature anomaly in XIS3. CCD temperature decreased
down to -93 degC, although the HK data showed incorrect value
around -70 degC. No significant impact on the data,
but the sensor might have slightly different gain.
6/7 5:48 - 7:31
Temperature anomaly in XIS2. The CCD temperature increased
up to -74 degC, although the HK data showed an incorrect value
around -102 degC. The XIS2 data in this period may have
significantly different performance in terms of the energy
resolution and the gain.
5/11 18:09 - 19:51
Temperature anomaly in XIS1. CCD temperature decreased
down to -92 degC, although the HK data showed incorrect value
around -45 degC. No significant impact on the data,
but the sensor might have slightly different gain.
5/11 16:27 - 18:10
Temperature anomaly in XIS0. CCD temperature decreased
down to -92 degC, although the HK data showed incorrect value
around -77 degC. No significant impact on the data,
but the sensor might have slightly different gain.
4/20 13:05 - 14:41
Temperature anomaly in XIS2. The CCD temperature increased
up to -80 degC, although the HK data incorrectly showed the nominal
temperature of -90 degC. The XIS2 data in this period may have
significantly different performance in terms of the energy
resolution and the gain.
3/29 20:13 - 23:11
No XIS FI (S0,S2,S3) data.
The sensors stayed in the standby mode due to the operation error.
3/15 2:18 - 3:02
XIS1 light leak error. Light leak estimation became incorrect
during the micro-code upload. XIS1 data in this period may not
be usable.
3/10 5:45 - 6:30
XIS1 light leak error. During the recovery operation from
the temperature anomaly mentioned above, light leak estimation
became incorrect. XIS1 data in this period may not be usable.
3/10 5:06 - 5:45
Temperature anomaly in XIS1. CCD temperature decreased
down to -92 degC, although the HK data showed incorrect value
around -45 degC. No significant impact on the data,
but the sensor might have slightly different gain.
2/17 22:12
Event threshold of FI sensors was changed to 100 adu.
2/17 13:56 - 15:37
Temperature anomaly in XIS1 CCD temperature decreased
down to -92 degC, although the HK data showed incorrect value
around -84 degC. No significant impact on the data,
but the sensor might have slightly different gain.
2/13 16:15
Soft current limit of TEC was reduced to 92% to avoid excess
thermal stress to the XIS heat sink assembly. After this,
CCD temperature might show temporary excursion of a few
degrees, which has no impact on the data quality.
2/8 15:02
Event threshold of FI sensors was changed to 60 adu.
2/2 12:42 - 19:50
No XIS data due to the bug in the microcode.
1/18 2:50 - 1/20 8:00
XIS on-board software update. Data obtained in this period
may or may not be usable for scientific analysis. After this
software update, G7-equivalent grades were rejected on board.
Light-leak estimation regions were changed from 64x64 to
256x113(114). Event threshold of FI sensors was changed from
100 adu to 50 adu.
1/5 5:49 - 7:31
Temperature anomaly in XIS1. CCD temperature decreased
down to -93 degC, although the HK data showed incorrect value
between -65 - -74 degC. No significant impact on the data,
but the sensor might have slightly different gain.
2005
12/06 6:55 - 7:16
Charge injection. Many pseudo-events were telemetered.
11/27 1:04 - 2:46
Temperature anomaly in XIS1. CCD temperature decreased
down to -92 degC, although the HK data showed incorrect value
between -81 - -88 degC. No significant impact on the data,
but the sensor might have slightly different gain.
11/22 14:33 - 11/23 2:48
Temperature anomaly in XIS0. CCD temperature decreased
below -90 degC, although the HK data showed incorrect value
of -83 degC. The data may be usable, but the sensor might
have slightly different gain.
10/21 22:45 - 10/22 1:30
Timing mode with no line summation.
This was a test operation and no scientific data were acquired.
10/21 21:05-21:25
Charge injection. Many pseudo-events were telemetered.
10/17 0:15-2:00
XIS1 operation error due to the bug of the microcode.
10/4 8:24 - 10:09
Temperature anomaly in XIS0. The CCD temperature increased
up to -70 degC, although the HK data showed incorrect value
of -104 degC. The XIS0 data in this period may have significantly
different performance in terms of the energy resolution and the gain.
9/4 4:55 - 15:39
Temperature anomaly in XIS0. CCD temperature decreased below
-90 degC, although the HK data showed incorrect value of -80 degC.
This may have been caused by the incorrect self-calibration of the
ADC due to the particle event just after the SAA passage. The data
may be usable, but the sensor might have slightly different gain.
8/29 2:20 - 2:26
Charge injection. Large number of pseudo-events were telemetered.
8/19 4:10 - 9:14
Error in light-leak estimation.
Size of the light-leak regions was increased from 64x64 to
256x256, which caused an error in the light-leak estimation.
The size was set back to 64x64 at 8/19 9:14.
Data from all the sensors in this period are not usable.
8/13 6:00 XIS-S2 door open.
7:40 XIS-S1 door open.
9:20 XIS-S0 door open.
8/12 7:41 XIS-S3 door open.
