1. HXMT Coordinated Observation Shaolin XIONG On behalf of HXMT SGS team Institue of High Energy Physics, China 11th IACHEC, IUCAA, PUNE (Mar 1, 2016)

2. In-flight calibration (1): PSF
High Energy tel.
NaI/CsI
keV, ~5000 cm2
Medium Energy tel.
Si-PIN
5-30 keV, ~950 cm2
Low Energy tel.
SCD (CCD236)
1-15 keV, ~380 cm2
Collimators for HE/ME/LE
Scan the constant bright 'point' source (Crab or PSR B )
Crab exposure: ~ 40 ks
Crab is visible from Sep. to Mar. 2

3. In-flight calibration (2)(3):
RMF, ARF; Timing
High Energy tel.
NaI/CsI
keV, ~5000 cm2
Medium Energy tel.
Si-PIN
5-30 keV, ~950 cm2
Low Energy tel.
SCD (CCD236)
1-15 keV, ~380 cm2
RMF&ARF
Absolute ARFs need to be calibrated in-flight
Pointing observing the Crab or other sources cross calibrated with others
Adjust RMF and ARF to fit the observed data with the “known” source spectrum
Timing
Observe the Crab/PSR B
10ks for Crab, 1Ms for PSR B 3

4. In-flight calibration (4): Energy-Channel and FWHMHE
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
Gain & FWHM varies with Temp.
Measured on ground
Calibration Sources
Radioactive sources on-board
Fluorescent lines
Sources with line features
(1 – 30 keV)
Tycho Spectrum
Fe Kα Line, 126ks(3 σ) obs is needed 4 4

5. In-flight calibration (5): Bkg model
Cross calibrate the blank sky (~ deg)?
CXB is anisotropic
Especially for LE (< 7 KeV) where CXB dominates the BKG
Known sources and Blank sky (blue circle for HXMT, red circle for RXTE) 5

6. In-flight calibration (6): Response of the spacecraft
GRB monitor
Use CsI (200 keV - 3 MeV) detector of HE
Approximately all-sky monitoring
Energy response calibration will not be calibrated on ground
Simultaneous GRBs by Fermi, Swift, Integral, Konus-Wind, etc.
GRB
GRB 6

7. List of In-flight Calibration Sources
Source Name RA
DEC
Usage
Crab
83.63
22.01
RMF, ARF; Timing; PSF, boresight
PSR B
228.48
-59.14
Cas A
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
4.3899
Background
(include: night Earth)
Blank Sky #2
Blank Sky #3
8.8014
Blank Sky #4
Blank Sky #5
Blank Sky #6
Blank Sky #7
Blank Sky #8
Other (IACHEC) sources?
HXMT Initial Calibration phase: – (TBC) 7 7

8. HXMT visibility to some sources
Blank sky 8 8