0. Table of contents
Last Updated 7 May 2020
1. Timing Calibrations of X-ray missions
1.1 Summary of Timing Requirement and Calibrations
| Mission/Instruments | Science Requirement Absolute Time | Timing System Design | Timing Calibration Status | In-orbit Timing Calibration Targets | Reported Issues | Reference | ||
|---|---|---|---|---|---|---|---|---|
| Requirement | Goal | GPS Receiver | Clock Stability | (Absolute Timing Precision) | ||||
RXTE/PCA  | ||||||||
| Chandra / ACIS | ||||||||
| Chandra / HRC | ||||||||
| XMM-Newton/EPIC-MOS | ||||||||
| XMM-Newtion/EPIC-PN | ||||||||
| INTEGRAL/SPI | ||||||||
| INTEGRAL/IBIS | ||||||||
| Swift/BAT | ||||||||
| Swift/XRT | ||||||||
Suzaku/XIS | No science requirement defined. | No | 1.9 x 10^-9 s/s | Not confirmed. | A0535+262, Her X-1, etc | N/A | Y.Terada et al 2008 (10.1093/pasj/60.sp1.S25) | |
| Suzaku/HXD | 360±150 μsec (270±130 μsec in condition) | Crab for coordinated PSR1509-58 | Timing shift by a failure in time stamp at the ground station during 2012-2014 (Shu Koyama, Fixed) | |||||
| NuSTAR/FPM | Should be 100 ms | none | No | Freely drifting by ~3 ms/day. | 65 us (1-sigma) | Crab | ~5ms offset using Corrected through | Bachetti+ in prep (can distribute early copy) |
| Astrosat | ||||||||
| HXMT | ||||||||
| Hitomi/SXS, SXI, HXI, SGD | 350 μsec | 35 μsec | Yes | 0.01μsec(GPSR) | ~ 120-230 μsec | Crab (with radio) note: using out-of-time event for SXI | absolute timing accuracy is much larger than expected on ground (3 μsec) | Y.Terada et al 2018 (10.1117/1.JATIS.4.1.011206) |
| NICER | 100 ns (RMS) | none | Yes | N/A | Approx. 3 µs | Crab Pulsar PSR B1821-24A PSR B1937+21 | Precise 1-second offset in on-board timestamps due to flight software bug; corrected using TIMEZERO keyword in pipeline-processed FITS data files. | Markwardt et al. (in prep.) |
| eROSITA | ||||||||
XRISM/Resolve  | 1 msec | none | Yes | same as Hitomi | (under discussion) | |||
| XRISM/Xtend | 10 msec | none | Yes | (under discussion) | ||||
Mission completed.
Future Mission
1.2 Point of Contacts
| Mission | PoC |
|---|---|
| RXTE | to be confirmed |
| Chandra | Vinay Kashyap |
| XMM-Newton | Felix Fuerst, Simon Rosen |
| Swift | Amy Lien |
| INTEGRAL | Guillaume Belanger, Volodymyr SAVCHENKO |
| NuSTAR | Matteo Bachetti, Katja Pottschmidt |
| Astrosat | Gulab Dewanga, (Dipankar Bhattacharya; to be confirmed) |
| HXMT | Xiaobo LI |
| NICER | Craig Markwardt, Teruaki Enoto |
| eROSITA | to be confirmed |
| Suzaku | Yukikatsu Terada |
| Hitomomi | Yukikatsu Terada |
| XRISM | Yukikatsu Terada |
2. In-orbit Timing Calibration Plan/Observations
2.1 Archive Data
2.1.1 List of Coordinated Observations useful for Timing
2.1.2 Reports
2.2 New Coordinated Observations
3. Studies on Timing
3.1 effects on timing products (power spec, light curve etc) by the detector’s behavior (dead time, grade selection of calorimeter etc)
4. Timing Tools, (with Statistic Group)
5. Notes