1. The Hard X-ray Modulation Telescope Mission
LU Fangjun
Particle Astrophysics Center

2. One-Three-Five Development Plan
One Development Strategy
To position IHEP to be one of world’s leading high energy physics research centers and a world-class, large, comprehensively multidisciplinary research base.
Three Major Goals
 Physics
 Major Facilities – To complete the construction of nation’s major science facilities: CSNS, ADS, HXMT and to improve BEPCII luminosity ;
 Application and Technology Transfer
Five Top Priorities
 Particle physics and astrophysics;
 Research in accelerator physics and technology;
 R&D in particle detection technology and associated electronics;
 Study of radiation sources and application of nuclear technology;
 Study of radiochemistry and related materials
HXMT: Hard X-ray Modulation Telescope

3. Outline Scienctific objectives Introduction to the Payloads
Project status and schedule
The HXMT team
Summary

4. Brief history of IHEP’s high energy astrophysics observations
1. Scientific objectives
Brief history of IHEP’s high energy astrophysics observations
IHEP’s High energy astrophysics observations began with balloon borne experiments in 1970s.
Most of the data used in astrophysics research are from European or US satellites, such as COS-B, EXOSAT, ROSAT, RXTE etc.
Balloon borne experiments

5. 1. Scientific objectives
(a) The input intensity distribution. (b) Convolution of the intensity distribution with the point spread function of a collimated telescope. (c) Restoration from a Monte-Carlo sample from (b). (d) is obtained by subtracting the background distribution from (c). The total number of photons from the point source is 120 and that from extended background is 1500.
Li & Wu, 1993, Ap&SS, 206,91
In 1990’s IHEP scientists developed an image reconstruction method named “the direct demodulation method”, which solves the observation equations iteratively under physical constraints, and can obtain high sensitivity and resolution images from noisy data.

6. Map by Cross-correlation Map by D-D method
Comparison of cross-correlation and direct demodulation imaging of the EXOSAT/ME Galactic plane scan observations.
Lu et al., A&AS 115, 395 (1996)
Map by Cross-correlation
Map by D-D method
The galactic center region from HEAO1-A4 all-sky survey ( keV).
Lu et al., Proc. CHEP’95, 848 (1995)
Original Data
Map by D-D method

7. 1. Scientific objectives
Based on the direct demodulation method and the experiences obtained in balloon borne hard X-ray experiments, IHEP proposed the Hard X-ray Modulation Telescope project in 1993.
It contains 18 NaI/CsI phoswich scintillators with a total detection area of 5000cm2, aiming for a hard X-ray ( keV) all-sky survey and pointed observations.
The mission was officially approved in March 2011.

8. 1. Scientific objectives
< 2005
2005
2006
2010
Optimised for the working temperatures of the detectors
Medium Energy X-ray Telescope added
High energy X-ray telescopes only
Low energy X-ray telescope added
Evolution of the payloads onboard HXMT

9. 1. Scientific objectives
Satellite Facts:
Weight: ~2800 kg
Orbit: 550 km, 43°
Attitude: 3-Axis Stabilized
precision 0.1 °
Lifetime: 4 years
Observation modes: Scan and pointing
HXMT collaboration
Institute of High Energy Physics (PI institute, payloads, scientific operation)
Chinese Academy of Space Technology (satellite platform)
National Space Science Center, CAS (space environment monitor, mission operation)
Tsinghua University (participation in payloads and scientific operation) 9

10. 1. Scientific objectives
Sciences with HXMT
Large sky-area scan
Diffuse X-ray emission: cosmic X-ray background; X-ray emission from the Galactic ridge and the Galactic center region
Detection of new (transient) sources and constrain their broad band (1-250 keV) properties
Follow up observation of gravitational wave bursts
Pointed observations
X-ray binaries: multiwavelength temporal behaviors, broad band spectra and Fe emission line
Equation of state in strong magnetic field: AXP, X-ray Bursts
Monitoring of Blazars and bright AGNs 10

11. Diffuse X-ray background
1. Scientific objectives
Diffuse X-ray background
Blocked: only sensitive to local particle induced bkg
Broad: source + diffuse X-ray bkg+ local bkg
Narrow: source + diffuse X-ray bkg+ local bkg
Advantages of HXMT’s FOV
(Türler et al. 2010, A&A 512, 49)
With the blocked, narrow, and broad FOVs, HXMT can subtract the charged particle induced background and can estimate the relative contributions of point source and diffuse background, and can thus give reliable measurements of the cosmic X-ray background in keV. 11

12. Detection of transient sources
1. Scientific objectives
Detection of transient sources
HXMT will scan the Galactic Plane frequently, in which new transient sources could be discovered and the high state of a known X-ray binary could be detected.
A quick look software will give the position and flux of the transient source every day.
When an X-ray source is found in high state, the telescope will do pointed observations according to the decision of the PI.
Transient source 12

13. 1. Scientific objectives
HXMT will do time resolved broadband spectroscopy for the brightest X-ray binaires.
Broad Fe-Kα line of XTE J by
XMM-Newton pn (Credit: ESA/XMM-Newton)
Illustration of a black hole X-ray binary
Mission
Spectral resolution
6keV)
Timing resolution
(ms)
Energy coverage
(keV)
Detection Area
Strongest sources without pileup
(Crab)
HXMT
150 1
240
No limit
XMM-Newton (pn, timing mode)
0.03
0.5-10
800
0.085
Chandra (ACIS, cc mode)
2.7
0.5-8
300
0.02
RXTE
1200
0.006
2-250
6000

14. 2. Introduction to the payloads
Star tracker
ME:Si-PIN,5-30 keV, 952 cm2
LE:SCD,1-15 keV, 384 cm2
Size：1900×1650×1000 mm
HE: NaI/CsI, keV, cm2

15. The High Energy X-ray Telescope (HE)
2. Introduction to the payloads
The High Energy X-ray Telescope (HE)
HXMT/HE Components assembly
18 main collimated phoswich detectors
18 calibration detectors (automatic gain control)
18 charged-particle anticoincidence plates (6 top +12 lateral side)
3 particle monitors

16. The Medium Energy X-ray Telescope (ME)
2. Introduction to the payloads
The Medium Energy X-ray Telescope (ME)
ME uses 1728 Si-PIN detectors read out by 54 ASIC (application specified integrated circuit). The energy coverage of ME is 5-30 keV, and the total detection area is 952 cm2. The in-orbit working temperature of ME is -40 to -20 ℃

17. 2. Introduction to the payloads
The low Energy X-ray Telescope (LE)
2×2
CCD236
16 cm2
LE consists of 3 detector boxes, and each boxes contains 32 CCD 236 chips, which have a time resolution of 1ms and energy resolution of <140 eV keV) . The total detection area is 384 cm2. The in-orbit working temperature is between -80 to -40 ℃.

18. 2. Introduction to the payloads
HXMT/LE
INTEGRAL/IBIS
HXMT/ME
RXTE/HEXTE
HXMT/HE
NuSTAR
The sensitivities of the three telescopes of HXMT. The sensitivities of NuSTAR, INTEGRAL/IBIS and RXTE/HEXTE were reprinted from Koglin et al. (2005)3.

19. 2. Introduction to the payloads
Comparison between HXMT and other major hard X-ray telescopes
HXMT
RXTE
INTEGRAL/IBIS
SWIFT
NuSTAR
Energy Band (keV)
LE:
ME: 5-30
HE:
PCA: 2-60
HEXTE:
XRT:
BAT:
3-79
Detection Area
(cm2)
LE: 384
ME: 950
HE: 5000
PCA: 6000
HEXTE: 1600
2600
XRT: 110
BAT: 5200
9 keV
78 keV
Energy Resolution (eV)
6 keV
20 keV
keV
100 keV
6 keV
60 keV
60 keV
Time Resolution
(ms)
LE: 1
ME: 0.18
HE: 0.012
PCA: 0.001
HEXTE: 0.006
0.06
XRT: 0.14, 2.2,2500
BAT: 0.1
0.1
Sensitivity 3σ，105s, mCrab)
0.5
1.5
3.8 9
20 keV

20. 3. Project status and schedule
Measureing the weight center and rotation inertia of the telescope ( )
The Mechanical Model of the satellite was finished in The payloads and platform both passed the dynamical environment tests.
The mechanical model of the satellite in dynamical environment tests ( )

21. 3. Project status and schedule
The electric model of HXMT’s payloads in assembling and testing ( ).
The tests of the electric performance of the payloads were finished in Dec. 2012, and those of the whole satellite were finished in early March of 2013.

22. 3. Project Status and schedule
The payloads after thermal control coating
Some of the components jointed the vacuum tests
Vacuum thermal balance tests of the satellite were carried out in Dec, The quasi-qualification models of all the detectors joined the tests. Those of HE and LE worked well during the tests, but that of ME had some problems with the FPGA, which were fixed and tested early this year.

23. 3. Project status and schedule
The electric fitting of the qualification models are onging, and most of them (except the ME detector box) will be finished in this month. The space environment tests will be done in November and December.

24. 3. Project status and schedule
X-ray machine
13-70 keV band:
Monoenergy fraction >90%
Monochromaticity <1%
Background shielding box for the calibrated detector
Double crystal monochromator
We have successfully constructed a double crystal monochromator X-ray calibration facility for HE, and the other one for LE and ME will be finished before March 2014.

25. prototype for observation program draw up
3. Project status and schedule
prototype for observation program draw up
Observation visibility study
HXMT mission movement trajectory
Observation Schedule
Monitoring of payload working status
The detailed design of the scientific ground segments and the software requirements have been finished. We are writing the codes of the softwares, which will be finished in the first season of the next year.

26. 3. Project status and schedule
12/2012
We are here .
2015
12/2013

27. PI: Li, Tipei; Co-PI: Zhang, Shuangnan
4. The HXMT team
HXMT
PI: Li, Tipei; Co-PI: Zhang, Shuangnan
Payloads
Director: Wang, Huanyu
Chief Designer: LU, Fangjun
Scientific Ground Segements
Director: Wang, Huanyu
Chief Designer: Song, Liming
Science working group
Director: Zhang, Shuangnan
Coordinator: Feng, Hua (Tsinghua University)
General Technology group
15 people
>70 astrophysicists from all the major astronomy instituations in China
Calibration group
HE group
ME Group
LE Group
46 people

28. Scientific and Technical Leaders
Chief Desginer of Payloads,
Professor of IHEP
, Research Associate at Univ. of Mass.
, visiting scholar at MPE,
1996, PhD at IHEP.
PI of HXMT,
Professor of IHEP and Tsinghua University.
Academician of CAS.
LI Tipei
LU Fangjun
Co-PI of HXMT,
Professor of IHEP
Professor of Tsinghua University.
, Research Scientist at NASA/MSFC, Assistant Professor of UAH
, Postdoc at Univ. of Penn.
1989, PhD at Univ. of Southampton
Chief Desginer of SGS,
Professor of IHEP
, Visiting Scientist at Riken
1996, PhD at Nanjing University.
ZHANG Shuangnan
SONG Liming

29. 4. The HXMT team
HXMT general techonology group and the project office (11 people)

30. The high energy telescope group (8 people @IHEP; 8 @Tsinghua Univ.)
4. The HXMT team
Group Leader:
Dr. LIU Congzhan
The high energy telescope group (8 Univ.)

31. The medium energy telescope group (14 people)
4. The HXMT team
Group Leader:
Dr. CAO Xuelei
The medium energy telescope group (14 people)

32. The low energy telescope group (13 people).
4. The HXMT team
Group leader:
Prof. CHEN Yong
The low energy telescope group (13 people).

33. The HXMT Scientific Ground Segements group (13 people)
4. The HXMT team
Group Leader:
Prof. SONG Liming
The HXMT Scientific Ground Segements group (13 people)

34. 5. Summary Thank you for your attention!
IHEP proposed the HXMT satelite, which has unique capabilities for X-ray binary studies and the measurements the diffuse X-ray background.
IHEP is in charge of the constructions of the payloads, calibration facilities, and the science ground segments, in which many young people become experts. These are important for the future of China’s X-ray astronomy.
The satellite will be launched in The observational data will be opened to astrophysicists in China and world wide.
Challenges: to keep the project schedule and to have the instruments well calibrated.
Thank you for your attention!

35. Supplementary materials

36. Characteristics of the HXMT Mission
Detectors
LE: SCD, 384 cm2;ME : Si-PIN, 950 cm2
HE : NaI/CsI, 5000 cm2
Energy Range
LE: 1-15 keV;ME: 5-30 keV;HE: keV
Time Resolution
HE: 25μs; ME: 180μs;LE: 1ms
Working Temperature
HE: 18±1℃; ME: -50~-20℃; LE: ℃
Energy Resolution
LE: 6 keV
ME: 17.8 keV
HE: 60 keV
Field of View of one module
LE: 6°×1.6°; 6°×4°; 60°×3°; blind;
ME: 4°×1°; 4°×4°; blind;
HE: 5.7°×1.1°; 5.7°×5.7°；blind
Source Location
<1' (20σ source)

37. Orbit
Altitude: ~550 km ; Inclination: ~43°
Attitude
Three-axis stabilized
Control precision: ±0.1°
Measurement accuracy: ±0.01°
Data Rate
LE: 3 Mbps; ME: 3 Mbps; HE: 300 kbps
Payload Mass
~1000 kg
Nominal Lifetime
4 years
Working Mode
Scan survey, small region scan, pointed observation

38. Simulation of the in-orbit background of HXMT
Different background components of HE
Total background of HE varying with time
Background components of ME
Background components of LE
Simulation of the in-orbit background of HXMT

39. Short timescale varibility of black hole X-ray binaries up to 250 keV.
The hard X-ray detectors RXTE/HEXTE、Suzaku/HXD and BeppoSAX/PDS are too small (<1000 cm2) , and INTEGRAL/ibis and SWIFT/BAT are of too high background to study the short timescale hard X-ray varibilities of black hole X-ray binaries. HXMT, with the large detecting area (5000 cm2, keV) and the relatively small field of view (low background) , will provide unique opportunity for studies in this field.
Variability amplitude as a function of energy for several black hole binaries. (Kaaret 2004)