In-flight operation procedures

1. The HXMT in-flight calibration planShaolin XIONG, Shijie ZHENG, Liming SONGOn behalf of HXMT SGS teamInstitue of High Energy Physics, China11th IACHEC, IUCAA, PUNE (Feb 29, 2016)

2. In-flight operation procedures • Platform Functionality Test: ~ weeks • Time, pointing/scan, data, telemetry, SAA... • Performance Verification (PV) • verify/optimize the detector performance • Initial Calibration • Comprehensive tests. ~3 months • Science Obs.: pointing, survey & deep scan • Routine/Request Calibration Commissioning Phase Nominal Operation Phase 2

3. Performance Verification (PV)& In-Flight Calbiration Verification Verify the science-related performance of platform Pointing/scanning, slew rate, data transmission, etc. Verify/Optimize the payload performance Working Voltage, Thermal Control, Threshold setting, SAA Verify the Working Procedure of Ground Segment In-flight Calibration Methodology Measure the in-flight performance Adjust calibration data in CALDB derived from ground calibration Derive calibration products from CALDB Energy-Chan, Energy-FWHM; PSF, boresight; Eff. Area, RMF Time accuracy Uniformity between detectors *Background

4. In-flight calibration (1): PSF High Energy tel. NaI/CsI 20-250 keV, ~5000 cm2 Medium Energy tel. Si-PIN 5-30 keV, ~950 cm2 Low Energy tel. SCD (CCD236) 1-15 keV, ~380 cm2 Hard X-ray Modulation Telescope Collimators! ME HE LE

5. PSF & Boresight Offset • Scan the standard 'point' source (Crab or PSR B1509-58) (~ 12 deg × 12 deg), 34 ks • Calculate the PSF and boresight for each collimator 5

6. In-flight calibration (2): Energy-Channel and FWHM • HE • AGC with 241Am (1/det. unit) • Temp. range : 18 ± 2 °C • ME • 241Am (2/det. box) • Temp. range：-50 ~ 0 °C • LE • 55Fe (1/det. box) • Temp. range：-80 ~ -30 °C Fluorescent lines (73Ta)in HE • Calibration Source • Radioactive sources on-board • Fluorescent lines • Lines from celestial objects Monitoring the temp. dependence Tycho Spectrum Fe Kα Line, 126ks(3 σ) obs is needed 6

7. In-flight calibration (3): RMF, ARF, Eff. Area • Pointing observing the Crab or cross-calibration the same source with other telescopes • Adjust RMF and Eff. Area by fitting the observed data with the “known” source spectrum

8. In-flight calibration (4): Timing precision • Pointing observation the Crab/PSR B1509-58 • TOA (Time of Arrival) ~ 10 μs • Obs Time: 10ks for Crab 1Ms for PSR B1509-58 8

9. Background Estimation and Modeling • BKG components • CXB instant variable • Albedo instant variable • Particles instant highly variable • Radioactivated delayed highly variable • BKG Estimation Method • Multiple-FOV Method: Large FOV, small FOV, blind • Offset Pointing Method • Placing source offset from FOV center • ~ 10% of accuracy demonstrated by simulations • BKG Modeling • Mass model, Monte Carlo code, orbit environment, etc. • In-flight BKG calibration observations • Establish/Adjust the BKG model 9

10. In-flight calibration (5): Bkg model • BKG observations to the Blank sky and Night Earth • routine observations Known sources and Blank sky

11. List of In-flight Calibration Sources 11

12. Internal/External Cross-Calibration • Internal Cross-calibration Pointing observing the Crab or other sources Jointly fit HE/ME/LE data, check consistency and derive normalization factors between telescopes, etc. • Cross-calibration with external telescopes Observe the same source simultaneously Adjust HXMT CALDB to match the calibrated telescopes Broad energy band for HXMT(1-250 keV) Please help us!

13. Summary • HXMTwill launch around Nov 2016 • In-Flight Calibration (initial cal. + routine cal.) PSF & boresight Energy-channel, FWHM PSF, ARF, Eff. Area Timing precession Background (blank sky, night Earth) • HXMT is open for collaborations! Cross-calibration & Guest proposals Thank you!