Brief Overview of China’s Future
Space X-ray Astronomy Program
Shuang-Nan Zhang
Center for Particle Astrophysics
Institute of High Energy Physics
Chinese Academy of Sciences
Outline
• Approved missions: launch within the next 5 years
– Hard X-ray Modulation Telescope (HXMT)
– Space Variable Object Monitor (SVOM): China-France
collaboration (Barret’s Talk)
– Gamma-ray burst polarimeter (POLAR): China-Europe
collaboration on China’s Spacelab
• In mission definition and technology development phase:
launch within next ~10 years
– X-ray Timing and Polarization mission (XTP)
• Proposed onboard China’s Space Station: launch around
2021-2022
– Optical/UV/X-ray All-Sky Monitor
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Payload Cabin
Platform Cabin
HXMT is a collaboration between:
Chinese Academy of Sciences, Tsinghua University
Chinese Academy of Space Technology
HE: NaI/CsI 5000 cm2
LE:SCD,384 cm2
ME:Si-PIN,952 cm2
Payloads onboard HXMT
Size：1900×1600×1000 mm3
LE
The Sun
A sunshading board will be set so that the LE and ME
instruments can work at low temperatures
5/37
High Energy X-ray Instrument
HXMT/HE Components assembly
• The 18 main collimated phoswich detectors
• Charged-particle anticoincidence plates (6 pieces up side +12
lateral side)
• Particle Monitor detectors
• Calibration detectors (automatic gain control)
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The Field of View configuration of HE
2 Modules of
5.7 °× 5.7 °
1 Blind Module
15 Modules of
1.1 ° × 5.7 °
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Detector:
Si-PIN
Energy coverage: 5-30 keV
Detecting area:
~950 cm2 (1728 pixels)
Sensitivity:
0.5 mCrab
Field of view:
1°×4°,4 °×4°, blind field
Energy resolution: < 1.5 keV@17.8keV
Work temperature: -20~-40℃ for Si-PIN
Time resolution:
40 μs
Mass:
105kg
Power dissipation: 130 W
16 Si-PIN (0.56 cm2 each) pixels will be in one package and 2
packages read by a RENA-3 asic.
9/37
The low energy instrument (LE)
2×2
CCD236
16 cm2
FOVs of an LE module
The Hard X-ray Modulation Telescope @ EAMA-7
11/37
Detector:
SCD
Energy coverage: 1-15 keV
Charge flow
Detecting area:
~384 cm2 (96 chips)
Sensitivity:
0.5 mCrab
Field of view:
1.5°×6°,4 °×6°, blind field
60 °×3°(48cm2),
Energy resolution: <150 eV@6keV
Work temperature: -40~-80℃ for SCD
Real & dummy
outputs in gap
Time resolution:
1 ms
Mass:
105 kg
Power dissipation: 130 W
Schematic map of a CCD236 (e2v)
Characteristics of the HXMT Mission
Detectors
LE: SCD, 384 cm2;ME : Si-PIN, 952 cm2
HE : NaI/CsI, 5000 cm2
Energy Range
LE: 1-15 keV;ME: 5-30 keV;HE: 20-250 keV
Time Resolution
HE: 25μs; ME: 20μs;LE: 1ms
Energy Resolution
LE: 2.5% @ 6 keV
ME: 8% @ 17.8 keV
HE: 19% @ 60 keV
Field of View of one LE: 6°×1.5°; 6°×4°; 60°×3°; blind;
module
ME: 4°×1°; 4°×4°; blind;
HE: 5.7°×1.1°; 5.7°×5.7°；blind
Source Location
<1' (20σ source)
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Sensitivity (3σ, in
105s)
LE: 4.4×10-5 cts cm-2s-1 keV–1 (@6keV)
ME: 2.6×10-5 cts cm-2s-1 keV–1 (@20keV)
HE: 3×10-7 cts cm-2s-1 keV–1 (@100keV)
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, pointed observation
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Scientific objectives of pointed observations
• X-ray Binaries
– Broadband X-ray variability, especially the QPO properties of BH
binaries at energy higher than 20 keV;
– Broadband spectral characteristics and state transitions
• Cyclotron Resonance Features (CRF) close to the neutron star
surface;
• Broadband spectrum of bright AGN: reflecting components and
high energy cut off;
Observation modes
• Scanning Sky Survey mode
• Deep scanning observations of selected sky
regions (such as the Galactic center region)
• Pointed observations
Status of HXMT
Full-funding decision: March 2011
• Phase-B (pre-flight module): 2011.6-2012.12
• Phase-C (flight module):
2013.1-2014.6
• Launch:
~2015
Outline
• Approved missions: launch within the next 5 years
– Hard X-ray Modulation Telescope (HXMT)
– Space Variable Object Monitor (SVOM): China-France
collaboration (Barret’s Talk)
– Gamma-ray burst polarimeter (POLAR): China-Europe
collaboration on China’s Spacelab
• In mission definition and technology development phase:
launch within next ~10 years
– X-ray Timing and Polarization mission (XTP)
• Proposed onboard China’s Space Station: launch around
2021-2022
– Optical/UV/X-ray All-Sky Monitor
18/37
Gamma-ray burst polarization experiment
onboard China’s Spacelab: POLAR
GRB prompt emission polarization:
a last observables of GRBs
•Different GRB models
– E-M Model: well defined, moderate Plin
~ 50%
– Fireball Model: high values excluded
Plin ~ 10-20 %
– Cannon ball Model: full range possible
Plin = 0 - 100%
•Probe quantum gravity (???):
– Amelino-Camelia G., 2000, Nature, 408,
661
– Piran T, 2005, Lect. Notes Phys, 669,
351
From M. Lyutikov, 2003
– Fan, Y-Z; Wei, D-M; Xu, D. 2007,
See papers discussing various GRB models:
MNRAS, 376, 1857
T. Piran, A. Dar, M. Lyutikov, D. Eichler, G.
Ghisellini, D. Lazzatti, M. Medvedev, E.
Rossi etc.
19/37
Gamma-ray burst polarization experiment
onboard China’s Spacelab: POLAR
• Onboard China’s spacelab
TG-2: launch time 2012-13
• A China-led international
collaboration (Switzerland,
France, Poland)
• FOV of POLAR: ~½ sky
Tian-Gong 天宫
Palace in Heaven
Plastic scintillator
stacks
Instrument concept proposed by N.
Produit, et al., NIM (2005) 20/37
POLAR capability summary
One year observation of POLAR
180
TS2/DM2 FOV = 2π
160
Number of GRBs (N < MDP)
140
•10 GRBs per year down to 8%, or
•60 GRBs per year down to 30%, or 100
GRBs per year down to 50% polarization,
120
100
80
60
40
20
0
0
10
20
30
40
50
60
70
80
Minimum Detectable Polarization with 3σ (%)
90
100
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Outline
• Approved missions: launch within the next 5 years
– Hard X-ray Modulation Telescope (HXMT)
– Space Variable Object Monitor (SVOM): China-France
collaboration (Barret’s Talk)
– Gamma-ray burst polarimeter (POLAR): China-Europe
collaboration on China’s Spacelab
• In mission definition and technology development phase:
launch within next ~10 years
– X-ray Timing and Polarization mission (XTP)
• Proposed onboard China’s Space Station: launch around
2021-2022
– Optical/UV/X-ray All-Sky Monitor
22/37
X-ray Timing and Polarization (XTP) mission
• Key Science: Matter under extreme conditions
• Precise Light curve: Neutron Star equation of state, BH
basic parameters, formation and growth …
• Polarization of X-ray: Radiation mechanism…
• Diffuse X-ray emission, hot gas distribution in Galaxy
• …
• Main Requirement: large effective area & high counting rate
• The most accurate light curve and polarization
observation at 1-30 keV
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HERO concept: High Energy Replicated Optics – Small
Aperture, Short Focal Length and Shallow Grazing Incidence
Using small mirror array to
achieve large collection area
at hard X-ray (>10 keV):
technically more feasible
than single large mirror.
Ramsey et al, SPIE 2000
24/37
Bepicolombo soft X-ray (<10 keV)
MPO telescope: short focal length & lightweight
2009-11-19
25
25/37
XTP Mission Concept
26/37
XTP (Possible) Instruments
SDD/CZT
High-energy Collimated
Array (1-100 keV)
High-energy Focused
Array (1-100 keV)
All Sky Monitor
(5-300 keV)
SDD/CZT
CZT
GEM
CCD
SCD
4m
focal
length
Polarization Observation
Telescope (2-10 keV)
Low-energy Focused
(0.5-10 keV)
Low-energy Collimated
Array (0.5-15 keV)
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LFA: Low energy有效载荷初步方案
X-ray Focusing telescope Array 0.5-10 keV
Micro-pore Optics (MPO) mirrors, mDEPFET detectors
MPO光学原理
矩形微通道排列
环形微通道排列
28/37
High energy X-ray Focusing telescope Array (HFA): 1-100 keV
Double conical nested mirrors
SDD+CZT composite detector
29/37
Low energy x-ray Collimated detector Array (LCA): 0.5-15 keV
SCD: e2V
一个LCA模块示意图
LIGA made collimator: 30μm
thickness each layer
30/37
HCA: High energy X-ray Collimated detector Array 1-100 keV
HCA composite detector
31/37
POT: Polarization Observation Telescopes 2-10 keV
掠射望远镜可通过国际合
作由意大利INAF研制，图示
为意大利原为HXMT设计的多
层掠射镜的装配图。
GEM-TPC: 0.25-30 keV
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ASM: All-Sky Monitor
FOV~2Sr, 4-300 keV, 1000cm2, 6400 × 4mm×4mm CdZnTe
33/37
XTP Basic Parameters
HFA：1-100 keV, 480 kg, 1°×1°, 1’
LFA：0.5-10 keV, 170 kg, 1°×1°, 1’
Energy
Range, HCA：1-100 keV, 500 kg, 2°×2°
Weight, FOV & LCA：0.5-15 keV, 400 kg, 2°×2°
Angular Resolution ASM：4-300 keV, 100 kg, 2 Sr
POT：2-10 keV, 110 kg, 22’ ×22’
Total satellite mass: 3210 kg
Geometrical Area
Energy Resolution
Timing Resolution
HFA: 5000 cm2 (1-6 keV), 2800 cm2@30 keV
LFA：7400 cm2@1 keV
HCA: 15000 cm2 (6-30 keV)
LCA: 15000 cm2 (1-6 keV)
150 eV@5.9 keV
4 keV@30 keV
10 μs
May choose near-earth orbit or L2 orbit, depending on available launcher (money)
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Outline
• Approved missions: launch within the next 5 years
– Hard X-ray Modulation Telescope (HXMT)
– Space Variable Object Monitor (SVOM): China-France
collaboration (Barret’s Talk)
– Gamma-ray burst polarimeter (POLAR): China-Europe
collaboration on China’s Spacelab
• In mission definition and technology development phase:
launch within next ~10 years
– X-ray Timing and Polarization mission (XTP)
• Proposed onboard China’s Space Station: launch around
2021-2022
– Optical/UV/X-ray All-Sky Monitor
35/37
OUVX-ASM Mission Concept
One X-ray ASM Module
zenith
FOV of
OUV-ASM
Motion of
spacecraft
FOV of X-ASM
36/37
Summary on China’s Future Space
X-ray Astronomy Program
• Approved missions
– Hard X-ray Modulation Telescope (HXMT): 2014-2015
– Space Variable Object Monitor (SVOM): China-France
collaboration (Barret’s Talk) ~2015
– Gamma-ray burst polarimeter (POLAR): China-Europe
collaboration on China’s Spacelab 2012-2013
• In mission definition and technology development phase
– X-ray Timing and Polarization mission (XTP) ~2020
• Proposed onboard China’s Space Station
– Optical/UV/X-ray All-Sky Monitor ~2021-2022
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