ACIS
ACIS DOSE Registered-Photon-Map
The steps we took to compute the dose map are;
- Level 1 Event files for a specified month are obtained from archive.
- Image data including I2, I3, S2, S3 CCDs are extracted from all event files.
- All the extracted image data were merged to create a month long exposure map for the month.
- The exposure map is opened with ds9, and check a distribution of count rates against energy. From this, estimate the upper threshold value. Any events beyond this upper threshold are assumed erroneous events such as bad pixels.
- Using this upper threshold, the data is filtered, and create a cleaned exposure map for the month.
- The exposure map from each month from the Sep 1999 is added up to create a cumulative exposure map for each month.
- Using fimgstatistic, we compute count rate statistics for each CCDs.
- For observations with high data drop rates (e.g., Crab nebula, Cas A), we corrected the observations by adding events.
Please check more detail plots at Telemetered Photon Dose Trend page.
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Statistics: # IMAGE NPIX MEAN RMS MIN MAX ACIS_oct25 6004901 4.296 6.075 0.0 2524 I2 node 0 262654 4.037679 2.325214 0.0 160.0 I2 node 1 262654 5.081691 2.784149 0.0 93.0 I2 node 2 262654 5.825274 3.376268 0.0 94.0 I2 node 3 262654 4.571972 4.558279 0.0 1760.0 I3 node 0 262654 4.984115 2.679160 0.0 86.0 I3 node 1 262654 4.967393 2.621744 0.0 120.0 I3 node 2 262654 4.794093 2.549912 0.0 72.0 I3 node 3 262654 4.725959 3.892431 0.0 1513.0 S2 node 0 262654 4.857380 6.774301 0.0 2524.0 S2 node 1 262654 5.309275 4.543634 0.0 590.0 S2 node 2 262654 5.826827 6.827510 0.0 2090.0 S2 node 3 262654 5.384052 5.703682 0.0 815.0 S3 node 0 262654 7.318428 6.989248 0.0 215.0 S3 node 1 262654 8.413095 6.945337 0.0 132.0 S3 node 2 262654 8.855959 8.168182 0.0 173.0 S3 node 3 262654 7.382217 7.581267 0.0 229.0
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Statistics: IMAGE NPIX MEAN RMS MIN MAX ACIS_total 6004901 2751.861 3473.040 0.0 169725 I2 node 0 262654 2390.086209 486.014467 511.0 16041.0 I2 node 1 262654 2521.988142 712.626901 522.0 167719.0 I2 node 2 262654 2549.318489 541.839160 547.0 17790.0 I2 node 3 262654 2552.345024 664.127744 505.0 37595.0 I3 node 0 262654 2759.215660 686.595866 506.0 15530.0 I3 node 1 262654 2837.803331 1758.883041 531.0 56084.0 I3 node 2 262654 2544.987590 478.142527 498.0 15614.0 I3 node 3 262654 2520.420621 515.232434 477.0 36710.0 S2 node 0 262654 3211.268953 519.637702 1730.0 22672.0 S2 node 1 262654 3411.973775 780.225831 1905.0 21860.0 S2 node 2 262654 3783.907464 784.172588 2320.0 34132.0 S2 node 3 262654 3740.559605 642.742813 2041.0 88477.0 S3 node 0 262654 5687.683364 3074.526653 2501.0 55564.0 S3 node 1 262654 6904.756544 2410.277468 0.0 83602.0 S3 node 2 262654 5639.193777 1383.730810 2659.0 27726.0 S3 node 3 262654 4437.974949 784.340178 2664.0 26821.0
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The Mean Detrended CTI
We report CTIs with a refined data definition. CTIs were computed for the temperature dependency corrected data. Please see CTI page for detailed explanation. CTI's are computed for Mn K alpha, and defined as slope/intercept x10^4 of row # vs ADU. Data file: here
Imaging CCDs
Spectral CCDs
Backside CCDs
Focal Plane Temperature
Oct 2025 Focal Temperature
| The Mean (max) FPT: | |
|---|---|
| -107.53 | +/- 7.69 C |
| Mean Width: | |
| 0.8 | +/- 0.58 days |
Averaged Focal Plane Temperature
We are using 10 period moving averages to show trends of peak temperatures and peak widths. Note, the gaps in the width plot are due to missing/corrupted data.
Focal Plane Temperature, Sun Angle and Altitude
Bad Pixels
The plots below were generated with a new warm pixel finding script. Please see Acis Bad Pixel Page for details.
Front Side CCDs
Back Side CCD (CCD5)
Science Instrument Background Rates
| Name | Low (keV) | High(KeV) | Description |
|---|---|---|---|
| SSoft | 0.00 | 0.50 | Super soft photons |
| Soft | 0.50 | 1.00 | Soft photons |
| Med | 1.00 | 3.00 | Moderate energy photons |
| Hard | 3.00 | 5.00 | Hard Photons |
| Harder | 5.00 | 10.00 | Very Hard photons |
| Hardest | 10.00 | Beyond 10 keV |
HRC
DOSE of Central 4K Pore-Pairs
Please refer to Maximum Dose Trends for more details.
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IMAGE NPIX MEAN STDDEV MIN MAX HRCI_10_2025.fits 16777216 0.001 0.026 0.000 1.000
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IMAGE NPIX MEAN STDDEV MIN MAX HRCI_08_1999_10_2025.fits 16777216 na na na na
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IMAGE NPIX MEAN STDDEV MIN MAX HRCS_10_2025.fits 16777216 0.009 0.098 0.000 3.000
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IMAGE NPIX MEAN STDDEV MIN MAX HRCS_08_1999_10_2025.fits 16777216 na na na na
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Max dose trend plots corrected for events that "pile-up"
in the center of the taps due to bad position information.
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Gratings
Grating Trends/Focus
We plot the width of the zero order streak of ACIS/HETG observations and the width of the zero order image for HRC/LETG observations of point sources. No significant defocusing trend is seen at this time. See Gratings Trends pages.
Gratings Resolving Power
We plot E/dE vs. E for fits to detected lines with fwhm_error/fwhm less than 0.15 for the plus and minus arms of HEG, MEG, and LEG. Also shown are conservative (dotted line) and optimistic (dashed line) pre-launch resolving power expectations.
We have selected only calibration observations of Capella, HR1099, and Sigma Gem. See MIT technotes for a parallel analysis.
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| Metg minus side | Metg plus side |
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| Hetg minus side | Hetg plus side |
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PCAD
ACA Trending
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Gyro Bias Drift
Radiation History
Radiation Count Rates of Oct 2025
Sun Spot History (See:NOAA Page)
SIM
SIM Shift and Twist
SIM Shift and Twist Trend The following plots show trends of SIM shifts (dy and dz) and twist (dtheta). All quantities are directly taken from pcaf*_asol1.fits files. The units are mm for dy and dz, and degree for dtheta. We fit three lines separated before and after (Days of Mission)= 1400 (May 21, 2003), 2700 (Dec 11, 2006), and 4400 (Aug 07, 2011). The unit of slopes are mm per day or degree per day.
The sudden shift around DOM = 1400, 2700 and 4400 are due to fid light drift (see a memo by Aldcroft fiducial light drift). On the dtheta plot, two tracks are clearly observed. The track around 0.01 is due to HRC-I, and all others are clustered around -0.002. For more detail, please see SIM Shift and Twist Trend page
Trending
Quarterly Trends
- EPS Batteries
| Previous Quarter | |||||||
| MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
| eb2ci | off | -5.618e-04 | 5.916e-05 | 0.31 +/- 0.14 | 0.00 +/- 0.00 | AMP | BATT 2 CHARGE CURRENT | on | -0.002 | 0.003 | 0.38 +/- 0.32 | (0.00+/-0.00)e0 |
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| eb2di | off | -6.918e-04 | 1.283e-04 | 0.03 +/- 0.30 | (2.09+/-6.00)e-5 | AMP | BATT 2 DISCHARGE CURRENT | on | 0.006 | 0.010 | 0.27 +/- 1.03 | (0.00+/-0.00)e0 |
| eb2v | off | 0.001 | 6.602e-05 | 32.28 +/- 0.16 | 0.00 +/- 0.00 | V | BATT 2 VOLTAGE | on | -0.007 | 0.004 | 32.17 +/- 0.46 | (0.00+/-0.00)e0 |
| ecnv1v | -2.077e-05 | 4.755e-06 | 14.89 +/- 0.01 | (6.32+/-6.01)e-4 | V | CONV 1 +15V OUTPUT | |
| ecnv2v | -4.739e-06 | 3.541e-06 | 14.83 +/- 0.01 | 0.00 +/- 0.00 | V | CONV 2 +15V OUTPUT | |
| ecnv3v | -2.715e-05 | 2.294e-06 | 15.28 +/- 0.01 | (1.44+/-3.65)e-4 | V | CONV 3 +15V OUTPUT | |
- Spacecraft Electronics
| Previous Quarter | |||||||
| MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
| elbi | 0.003 | 5.472e-04 | 53.23 +/- 1.28 | 0.03 +/- 0.16 | AMP | LOAD BUS CURRENT | |
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| elbv | off | 0.002 | 6.899e-05 | 27.82 +/- 0.17 | -0.04 +/- 0.02 | V | LOAD BUS VOLTAGE | on | 0.007 | 0.003 | 27.71 +/- 0.36 | (0.00+/-0.00)e0 |
- OBA Heater
| Previous Quarter | |||||||
| MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
| oobthr04 | 0.006 | 7.138e-04 | (3.03+/-0.02)e2 | 0.81 +/- 0.39 | K | RT 27: HRMA STRUT | |
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| oobthr12 | 0.008 | 0.001 | (3.01+/-0.02)e2 | 0.97 +/- 0.60 | K | RT 35: OBA CONE | |
| oobthr26 | 0.011 | 0.002 | (3.05+/-0.04)e2 | 1.18 +/- 0.91 | K | RT 48: OBA CONE | |
| oobthr38 | 3.574e-05 | 5.182e-06 | (2.72+/-0.00)e2 | 0.00 +/- 0.00 | K | RT 60: TFTE CONE | |
| oobthr44 | 0.008 | 0.001 | (3.04+/-0.02)e2 | 1.02 +/- 0.62 | K | RT 66: TFTE COVER | |
| oobthr50 | 0.008 | 8.899e-04 | (2.98+/-0.02)e2 | 0.90 +/- 0.52 | K | RT 76: S/C STRUT | |
Spacecraft Motions
TSC and FA Cummulative Moter Distance
HETG and LETG Cummulative Insertion Counts
HETG/LETG Insertion/Retraction Angle
Reaction Wheel Rotations
