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宇宙微波背景辐射

宇宙微波背景辐射. 郭宗宽. 中国科学院研究生院 2012.06.26. 交叉学科 -- 宇宙学. 宇宙学基本假设和理论基础 宇宙学原理（无边，无中心） 爱因斯坦引力理论 宇宙物质（重子 + 光子 + 中微子 + 暗物质 + 暗能量） 观测实验的重要性 超新星，大尺度结构， 宇宙微波背景辐射 宇宙射线， 21 厘米谱线，射电波，弱引力透镜，引力波，中微子 目前的进展和存在的问题 宇宙加速膨胀（暴涨，暗能量，修改引力，非均匀宇宙） 宇宙大尺度结构形成（冷 / 温 / 热暗物质，暗物质粒子的性质，暗物质分布）. 内容. 宇宙微波背景（ CMB ）辐射的形成

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宇宙微波背景辐射

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  1. 宇宙微波背景辐射 郭宗宽 中国科学院研究生院 2012.06.26

  2. 交叉学科--宇宙学 • 宇宙学基本假设和理论基础 宇宙学原理（无边，无中心） 爱因斯坦引力理论 宇宙物质（重子+光子+中微子+暗物质+暗能量） • 观测实验的重要性 超新星，大尺度结构，宇宙微波背景辐射 宇宙射线，21厘米谱线，射电波，弱引力透镜，引力波，中微子 • 目前的进展和存在的问题 宇宙加速膨胀（暴涨，暗能量，修改引力，非均匀宇宙） 宇宙大尺度结构形成（冷/温/热暗物质，暗物质粒子的性质，暗物质分布）

  3. 内容 • 宇宙微波背景（CMB）辐射的形成 • CMB的发现和探测实验 • CMB的数据分析 • CMB各向异性的物理起源 • CMB的宇宙学解释 • 展望

  4. 1. CMB的形成 • recombination • decoupling

  5. 2. CMB的发现和探测实验 • CMB was predicted by G. Gamow et al. in 1948 T~5 K • the first discovery of CMB radiation in 1964-1965 the Nobel Prize in Physics 1978: A.A. Penzias and R.W. Wilson • interpreted by P.J.E. Peebles, D.T. Wilkinson, et al. in 1965

  6. Hot big bang • COBE (Cosmic Background Explorer) - the first generation CMB experiment, launched on 18 Nov. 1989, 4 years the Nobel Prize in Physics 2006: J.C. Mather and G.F. Smoot J.C. Mather G.F. Smoot (DMR) isotropy

  7. the COBE satellite experiments: • the Far InfraRed Absolute Spectrophotometer (FIRAS) team • the Differential Microwave Radiometer (DMR) team • advantages of satellite experiments: • no atmospheric thermal emission • full-sky map

  8. WMAP (Wilkinson Microwave Anisotropy Probe) - the second generation CMB experiment, launched on 30 June 2001, 9 years 141°

  9. 23 GHz 33 GHz 41 GHz 61 GHz • free-free emission: electron-ion scattering • synchrotron emission: the acceleration of cosmic ray electrons in magnetic fields • thermal emission from dust 94 GHz

  10. foreground mask • angular power spectrum of CMB

  11. We have entered a new era of precision cosmology.!?

  12. Planck - the third generation CMB experiment, launched on 14 May 2009, 30 months, 5 full-sky surveys LFI: 30, 44, 70 GHz HFI : 100, 143, 217, 353, 545, 857 GHz

  13. nextgeneration CMB experiment • NASA: CMBPol • ESA: COrE

  14. Other experiments: • ground based experiments (QUaD, BICEP, ACT, ACTPol from 2013, SPT, SPTpol from 2012) • balloon borne experiments (BOOMRANG, MAXIMA) • South Pole Telescope (SPT) 10 meter telescope 150 and 220 GHz in 2008 95, 150 and 220 GHz in 2009

  15. Atacama Cosmology Telescope (ACT) 3 frequencies (148, 218, and 277 GHz) 6 meter telescope

  16. 3. CMB的数据分析 time-ordered data full sky map spectrum parameter estimates  time-ordered data  the temperature anisotropies can be expanded in spherical harmonics

  17.  for Gaussian random fluctuations, the statistical properties of the temperature field are determined by the angular power spectrum For a full sky, noiseless experiments,  cosmological parameter estimation likelihood function for a full sky: the sky-cut, MCMC

  18. 4. CMB各向异性的物理起源 • primary CMB anisotropies (at recombination) inflation model (Alan H. Guth in 1981) primordial power spectrum of curvature perturbations angular power spectrum of CMB anisotropies V (φ) inflation φ reheating

  19. for slow-roll inflation, the primordial power spectra of scalar/tensor perturbations: the coupled, linearized Boltzmann, Einstein and fluid equations: Fourier space spherical harmonics

  20. the Einstein equations: the linearized Einstein equations:

  21. secondary CMB anisotropies (after recombination) reionization thermal Sunyaev-Zel’dovich effect lensing effect integrated Sachs-Wolf effect

  22. features of spectrum • large angular scales integrated SZ effect (<10) Sachs-Wolf effect (10~100) • intermediate scales acoustic oscillations (100~1000) • small scales (>1000) Silk damping: the dissipation of small-scale perturbations caused by photons' random walking out of overdense regions. For full accuracy, the Boltzmann equation must be solved to follow the evolution of the photon distribution function.

  23. 5. CMB的宇宙学解释

  24. the content of our Universe precision cosmology The stronger the contraction, the higher these peaks should be.

  25. 6. 展望 • the shape of the primordial power spectrum of curvature perturbations • detection of the primordial power spectrum of tensor perturbations • non-adiabaticity • non-Gaussianity

  26. Thank you for your attention.

  27. a main-sequence star (hydrogen) • red giant (helium → carbon, oxygen) • white dwarf (carbon, oxygen): electron degeneracy pressure, 1.4 solar masses • Type Ia supernova • a main-sequence star (hydrogen, carbon, oxygen) • Type Ib, Ic, II supernova (a line of hydrogen) • neutron star (including pulsar): neutron degeneracy pressure, 1~2 solar masses • a main-sequence star (hydrogen, carbon, oxygen) • Type Ib, Ic, II supernova • black hole: 3.2 solar masses

  28. Adam G. Riess (High-Z), Saul Perlmutter (leader of SCP), Brian P. Schmidt (leader of High-Z)

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