X 射线和 γ 射线天文观测 王俊贤 中国科技大学天体物理中心

Transcription

1 X 射线和 γ 射线天文观测 王俊贤 中国科技大学天体物理中心

2 Introduction Cherenkov Telescope Detectors A brief history of X-ray astronomy X-ray targets Imaging technique X-ray observatories Future Cosmic X-ray Background (CXB)

3 High energy emission comes from regions with extreme high temperature or relativistic velocity

4 Photon energy unit kev Convert photon energy to wavelength 1 kev = 1.6 x 10-9 erg = hc/λ, λ=12.4å the ionization potential of hydrogen: 13.6 ev or 912Å Temperature 1 kev ~ 1.16 x 10 7 K (hν = kt) Doppler shift a UV photon at 1240Å to 1keV require a speed of c

5 1895 Conrad Röntgen The first Physics Nobel Prize Winner (1901)

6 Rapid growth of X-ray astronomy Simple detectors on rocket flight in 1962, equivalent to a naked eye in visible astronomy A billion times more sensitive today, comparable to 10 meter optical telescopes

7 X-ray 的光电吸收 Compton scattering 电子经典散射截面 6.65x10-25 cm 2

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10 Dust extinction versus X-ray absorption N H Galactic ISM

11 absorption line absorption edge

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13 X-ray scattering by dust X-ray halo Draine 2003

14 空气分子数密度 2.45x10 19 cm -3 空气中氧氮元素丰度 ~100% 太阳中金属元素丰度 ~0.2% 10 cm 空气中对应太阳金属丰度大气柱密度 ~ 2.5x10 23 cm -2

15 ninety percent of the photons in a beam of 3 kev X-rays are absorbed by traveling through just 10 cm of air! Three methods doing X-ray astronomy Rocket flights Balloons Satellites

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18 切伦科夫辐射

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21 切伦科夫望远镜

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23 切伦科夫 (Cherenkov) γ 射线望远镜 地面探测 γ 射线 利用高能 γ 光子与大气层 作用产生的切伦科夫辐射 高达 10 4 m 2 的集光面积

24 X-ray detectors 气体正比计数器 微通道板 闪烁计 CCD Single photon Calorimeter

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27 CCD 获得光子 时间 位置 能量 E/dE~10-50

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32 XRS on Suzaku

33 Superconducting Transition Edge Sensor(TES)

34 X-ray detectors

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36 A brief history of X-ray astronomy X-ray observatories X-ray targets

37 Riccardo Giacconi receiving his 2002 Physics Nobel Prize (with Raymond Davis, Jr. and Masatoshi Koshiba)

38 1949 年 Herbert Friedman 美国海军研究实验室 V2 火箭, 盖革计数器 太阳冕区的 X 射线辐射 仅占太阳全部辐射能量的百万分之一 未来的 X 射线观测???

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40 1962 A Group led by Riccardo Giacconi, Herb Gursky, Frank Paolini, and Bruno Rossi Proposed to detect X-ray from moon Funding provided by air force

41 A five minutes flight, detected Sco X-1 ( 天蝎座 X-1), XRB (Cosmic X-ray Background) Starts the era of X-ray astronomy As a footnote, X-ray from moon was not detected until 1990 by ROSAT

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43 X-ray binary

44 The Kinds of Objects in the Universe that X-ray Astronomers Observe There are a variety of different kinds of astronomical sources which emit electromagnetic radiation in the X-ray regime. These include: Active Galaxies Binary Star Systems Black Holes Cataclysmic Variables Dark Matter Diffuse Background Gamma-ray Bursts Neutron Stars Pulsars Stars The Sun Supernovae and their Remnants White Dwarfs X-ray Transients star forming galaxies IGM ULX

45 More rocket flights Comfirming the existence of XRB More X-ray sources Including X-ray binaries,m87 Demanding X-ray satellite

46 Uhuru Small Astronomical Satellite 1 (SAS-1) 1970 年 12 月 12 日发射, 适值肯尼亚独立纪念日, 故命名为 自由号 (Uhuru, 斯瓦希里语自由之意 ) The first earth-orbiting X-ray mission dedicated entirely to celestial X-ray astronomy Energy range 2-20 kev Two sets of proportional counters m 2 First uniform all sky survey 339 X-ray sources Diffuse emission from clusters Demanding X-ray telescopes

47 Uhuru ( Freedom ) Bruno Rossi Marjorie Townsend

48 Ariel V launch

49 Einstein X-ray Observatory (HEAO-2) First X-ray Observatory with mirrors Located ~ 7000 X-ray sources Show that XRB is likely due to discrete sources Study the spectrum of X- ray binaries and AGN

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51 The Wolter X-ray Telescope Designs

52 编码成像技术

53 ROSAT (Röntgensatellit)

54 ROSAT 1 June Feb kev All sky survey in soft X-ray band Position Sensitive Proportional Counter High Resolution Imager (2 ) X-ray all-sky survey catalog, > Resolves 70% soft X-ray background

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56 ASCA The Advanced Satellite for Cosmology and Astrophysics Feb 20, March 2, kev Spatial resolution 3 4 Wolter I telescopes Two imaging gas Scintillation Proportional Counters Two CCD arrays of four 420x422 chips

57 AGN accretion disc the `broad Fe Ka line MCG : Tanaka et al. (1995). Hard X-rays illuminate cold inner accretion disc Broad Iron Ka seen by Reflection

58 MCG XMM-Newton EPIC Wilms et al. (2001). Branduardi- Raymont et al. (2001). XMM-Newton RGS Fabian et al. (2002) (Blandford & Znajek 1977)

59 1999

60 X-RAY TELESCOPE

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64 Mirror diameter 1.2 m Spatial resolution < 0.5" (1 pixel) Field of view (ACIS-I) ~ 17' x 17' Band kev Spectral resolution up to 1000 (E/ E) Low noise level 造价 :15.5 亿美元, 加上航天飞机发射和在轨运行费用, 项目总成本 :28 亿美元

65 XMM-Newton

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68 XMM-Newton Dec 1999 (nominal 10 year mission) kev Larger collecting area (comparing with Chandra) European Photon Imaging Camera (2xMOS + 1PN) Reflection Grating Spectrometer ( kev) E/dE =

69 Astro-E2 (Suzaku)

70 X-rays on Ice The XRS X-ray microcalorimeter built for Astro-E (the fifth Japanese X-ray astronomy satellite) Resolution : 9-12 ev FWHM ( kev)

71 Inserting the He dewar in the Ne dewar A solid Ne dewar outside a liquid He dewar outside an adiabatic demagnetization refrigerator.

72 Astro-E Launch - February 2000

73 20 seconds and going well

74 Uh - oh

75 You really don t want to see this Astro-E was being rebuilt as Astro-E2 and was successfully launched in July Rebuilt calorimeter has resolution of 7 ev, but stopped working within a month.

76 Suzaku Five X-ray telescopes One X-ray spectrometer (XRS), microcalorimeter, kev Four X-ray imaging spectrometer (XIS) kev Hard X-ray detector (HXD) kev, no telescope

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78 X-ray mirrors above 10 kev Ordinary X-ray telescopes focus light below 10 kev Collimators, coded aperture masks, etc, were used for harder X-ray observations Focusing system would be > 1000 times more sensitive in harder X-ray Need multi-layer coated mirrors & long focus length

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80 Launched in June 2012

81 Launched in Feb Hitomi( 瞳 )

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83 Future X-ray mirrors above 10 kev Wide field X-ray surveys Next generation X-ray observatories Diffraction limited X-ray imaging X-ray polarimetry

84 erosita FOV: 0.83 deg 2 To be launched in 2018

85 erosita

86 WFXT

87 XEUS The X-Ray Evolving Universe Spectrometer

88 Constellation-X-X

89 Constellation-X Overview ouse X-ray spectroscopy to observe Black holes: strong gravity & evolution Large scale structure in the Universe & trace the underlying dark matter Production and recycling of the elements

90 XEUS+Con-X IXO

91 IXO

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95 X-ray Surveyor / Lynx NASA concept study, for submission to the Decadal 2020 survey Launch > 2030 (>>2030??)

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98 Diffraction-limited X-ray imaging Diffraction limited spatial resolution in X-ray is ~ times better than optical with same telescope aperture. Challenges: mirror coating satellite formation flying

99 MAXIM Micro Arcsecond X-ray Imaging Mission

100 X-Ray Interferometry

101 A larger separation between mirrors provides greater resolution. The MAXIM mission -- an X-ray interferometer large enough to image a black hole -- would entail a fleet of up to 33 optics spacecraft flying in formation with a precision of 20 nano-meter, plus a detector spacecraft 500 kilometers behind the mirrors. MAXIM would achieve 100 nanoarcsecond resolution. Flying the various parts of an X-ray interferometer in unison is tricky business. NASA is considering to first test the X-ray interferometer technique in space with a "pathfinder" mission. The MAXIM Pathfinder would have a one-meter separation between the mirrors so that all the X-ray optics are on one spacecraft. The MAXIM Pathfinder would provide 100 microarcsecond resolution.

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103 谢谢!