The HXMT in-flight calibration plan Shaolin XIONG, Shijie ZHENG, Liming SONG On behalf of HXMT SGS team Institue of High Energy Physics, China 11th IACHEC, IUCAA, PUNE (Feb 29, 2016)

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 2

Performance Verification (PV) & In-Flight Calbiration 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 3

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 4

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 5

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 6

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 7

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 8

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 9

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

List of In-flight Calibration Sources Source Name RA DEC Usage Crab 83.63 22.01 RMF, ARF, Timing, PSF, boresight, etc. PSR B1509-58 228.48 -59.14 Cas A 350.846 58.813 Data analysis, LE temperature drift Tycho 6.334 64.150 Cyg X-1 299.59 35.20 Data analysis, quick-look Sco X-1 244.98 -15.64 Mrk421 166.11 40.09 Blank Sky #1 145.9975 4.3899 Background (include: Night Earth) Blank Sky #2 176.4366 -20.6326 Blank Sky #3 232.5356 8.8014 Blank Sky #4 251.8799 55.7135 Blank Sky #5 322.4055 -24.2587 Blank Sky #6 52.6687 -59.8347 Blank Sky #7 312.2388 -11.8415 Blank Sky #8 22.5767 -76.1370 11 11

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! 12

Thank you! Summary HXMT will 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! 13