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The CMB and Gravity Waves

The CMB and Gravity Waves. John Ruhl Case Western Reserve University. 3/17/2006, CERCA at St. Thomas. WMAP 3yr temperature maps… what the sky really looks like. 23 GHz. 61 GHz. 33 GHz. 94 GHz. 41 GHz. (What the sky really looks like). WMAP 3-year map, “galaxy subtracted”.

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The CMB and Gravity Waves

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  1. The CMB and Gravity Waves John Ruhl Case Western Reserve University 3/17/2006, CERCA at St. Thomas

  2. WMAP 3yr temperature maps… what the sky really looks like. 23 GHz 61 GHz 33 GHz 94 GHz 41 GHz (What the sky really looks like)

  3. WMAP 3-year map, “galaxy subtracted”

  4. Boomerang “T” maps B03: 150GHz (published) 10’ resolution, ~1000 sq. deg.

  5. Acbar maps 150GHz, 5’ resolution, 10’s of sq. deg, More coming soon.

  6. <TT> Power spectra=> CDM looks good Power Spectrum (uK2) Legendre l

  7. B03 <TT> power spectrum=> CDM still looks good

  8. WMAP(3yr)+others <TT> Figure 18, Hinshaw etal, WMAP 3-year release

  9. WMAP 3yr data… theory-scaled to high-ell… Fig 5, Spergel etal, WMAP 3-year release

  10. “Post B03”(pre-WMAP3)parameters MacTavish etal, B03 release

  11. Still of interest r = T/S: primordial gravity waves (tensor modes) nT: spectral index of tensor mode power spectrum ns: spectral index of density perturbation power spectrum, Dark Energy w, w’, etc non-gaussianity Isocurvature modes Suprises: eg “not flat”, obs. disagreements, etc.

  12. CMB“goal” ns vs r : current limits WMAP 3yr, r<0.28 (95%CL) w/SDSS r T/S ns Plot from M. Tegmark, TFCR report

  13. CMB polarization Two causes: “Normal” CDM: Density perturbations at z=1000 lead to velocities that create local quadrupoles seen by scattering electrons. => “E-mode polarization” (no curl) Gravity waves: create local quadrupoles seen by scattering electrons, => “B-mode polarization” (curl)

  14. Both are caused by the polarization dependence in Thomson scattering

  15. Anisotropic illumination => polarization Green = probability of emitting in that direction… Observer Vertical pol. Line of sight No emission to observer Line of sight Horizontal pol.(in and out of page) Line of sight

  16. Gravity waves at z=1000 Gravity Wave Surface of last scattering

  17. … create local quadrupoles around an electron at z=1000.

  18. Flavors of CMB polarization Two patterns: Density perturbations: curl-free, “E-mode” Gravity waves: curl, “B-mode”

  19. Linear polarization Stokes parameters IAU convention for Q and U North North - East - East + + U Q Each point on the sphere has a Q or U value determined by the polarization at that point.

  20. Stokes Parameters vs. E and B mode The E-mode (or B-mode) value at a point on the sphere depends on the polarization pattern all around it. Direction you’re looking on the sky (2 components) Same thing, but variable for integration Polar coordinates of relative to Weighting function (Note: w=0 for theta =0)

  21. For a given circle ( ), circumference goes as , while , so the contribution of that circle goes as 1/ . E and B mode patterns Blue = + Red = - “local” Q “local” U

  22. E and B mode patterns E-mode Unchanged under parity flip B-mode Sign reverses under parity flip Seljak and Zaldarriaga, astro-ph/9805010

  23. E-mode polarization (simulation) Seljak and Zaldarriaga, astro-ph/9805010 Color: |E| Bars: E-mode polarization direction and size

  24. B-mode polarization (simulation) Seljak and Zaldarriaga, astro-ph/9805010 Color: |B| Bars: B-mode polarization direction and size

  25. Reionization bump Primordial B-modes CMB Polarization power spectra Shape and amplitude of EE are predicted by CDM. ``Shape” of BB is predicted “scale-invariand GW’s”. Amplitude of BB is model dependent.

  26. The State of CMB polarization measurements

  27. Fig 22, Hinshaw etal, WMAP 3yr release WMAP <TE>, Kogut etal

  28. EE power spectrum data

  29. EE power spectrum data Figure 22, Page etal, WMAP 3-yr release.

  30. B03 and WMAP 3yr

  31. High-l BB power spectrum data

  32. WMAP Polarization data Current “high-l” BB limits BB limit (1sigma) Foreground model r=0.3 BB Figure 25, Page etal, WMAP 3yr release

  33. The Future of CMB polarization measurements Foregrounds Technology

  34. Synchrotron Dust Foregrounds at l=50 r = 0.01 S. Golwala, 2005

  35. Galactic Foregrounds: l-space From G. Hinshaw, TFCR report

  36. “Future, large angular scale” CMB Polarization Experimentsdeployedfunded proposed Quad: NTD bolo, 90/150 GHz, ~0.2deg, ~100 elements. Spole. Bicep: NTD bolo, 90/150 GHz, ~1deg, ~100 elements, Spole Ebex: SC Bolos, 90-400GHz, ~0.2deg, ~1000 elements, balloon Pappa: SC bolos, 90/150GHz, ~1deg, ~20 elements, balloon Clover: SC bolos?, 90-220GHz?, ~1deg, ~1000 elements, Chile Quiet: Hemts, ??? freqs/elements, Chile Polarbear: SC bolos, 90/150/220GHz, ~0.2deg, ~? Elements, Chile Spider: SC bolos, 40-220GHz, ~1deg, ~1000 elements, balloon CMBPOL: ???, satellite [see TFCR (aka “Weiss”) report]

  37. Sensitivities 1 10 100 1000 1 10 100 1000 Plot from T. Montroy

  38. Predicted Future Experiment Sensitivities From G. Hinshaw, TFCR report

  39. Systematics to conquer Table 6.1 from TFCR report

  40. Experiment strengths and weaknesses

  41. Experiment strengths and weaknesses

  42. On-chip modulator(continuous) modulator photons Detector feed(s) Other optics “on chip”

  43. “After primary” modulator(continuous) feed(s) Other optics photons Detector modulator “on chip”

  44. “Ideal” Future experiment to probe Inflation • Lots of sensitive detectors and integration time • “Good enough” angular resolution (to measure l=100 bump) • “Large enough” sky coverage (to measure reionization bump) • Low systematics, polarization modulator… optimized for Polarization. Ultimate instrument: CMBPOL satellite Realistic (proposed) instrument…

  45. Spider(CMBPOL on a rope) Canada: U. Toronto, U.BC UK: Cardiff, Imperial Coll. London USA: Caltech, Case, JPL, NIST A balloone-borne“low l” machine

  46. Six frequency bandsSix telescopesClean refractor opticsHalfwave plates

  47. CIT/JPL Polarized Array8x8=64 pixel phased-array “patches”, 2 polarizations on each.

  48. JPL Antenna-coupled bolometer,and crossed dipole elements

  49. Around the world flight from Australia, night time observing only Large sky coverage => get to low l

  50. Spider baseline bands and sensitivities 6 bands 1856 detectors

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