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K. Ganga – CMB Science and Observations 1 Rencontres du Vietnam - 2006/08/09 CMB Science and Observations K. Ganga.

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Presentation on theme: "K. Ganga – CMB Science and Observations 1 Rencontres du Vietnam - 2006/08/09 CMB Science and Observations K. Ganga."— Presentation transcript:

1 K. Ganga – CMB Science and Observations 1 Rencontres du Vietnam /08/09 CMB Science and Observations K. Ganga

2 K. Ganga – CMB Science and Observations 2 Rencontres du Vietnam /08/09 The CMB The CMB is a blackbody at T = 2.73 K. The most prominent anisotropy in the CMB, with amplitude of about 0.1%, is due to our motion with respect to the CMB rest frame. Further anisotropies are at the level of 0.001% and lower (or much lower)

3 K. Ganga – CMB Science and Observations 3 Rencontres du Vietnam /08/09 Observer z =1000z = infinity Plasma Recombination T=2.73K Plasma Horizon ~1 o z =1000 Plasma Recombination Gravitational lensing T=2.73K Reionisation Observer The CMB again... Thanks to A. Taylor

4 K. Ganga – CMB Science and Observations 4 Rencontres du Vietnam /08/09 T on super-horizon scales (>1 o ) Sachs-Wolfe Effect: Gravitational redshift due to photons climbing out of potential wells, A. Taylor

5 K. Ganga – CMB Science and Observations 5 Rencontres du Vietnam /08/09 Acoustic Oscillations

6 K. Ganga – CMB Science and Observations 6 Rencontres du Vietnam /08/09 Measuring Curvature Flat Close d Open Acoustic horizon (same for all) v s t dec J. Ruhl B. Crill

7 K. Ganga – CMB Science and Observations 7 Rencontres du Vietnam /08/09 Baryons change the effective mass W. Hu

8 K. Ganga – CMB Science and Observations 8 Rencontres du Vietnam /08/09 How Parameters are Fit Parameters are found by making spectra for the range of models of interest and finding which has the best chi-squared given the actual data and some prior information. Angular spectrum varies mostly with b cdm H 0, n s

9 K. Ganga – CMB Science and Observations 9 Rencontres du Vietnam /08/09 'Degeneracies' require other data l peak /2 Simulated Pretty flat models tot = 1

10 K. Ganga – CMB Science and Observations 10 Rencontres du Vietnam /08/09 A little help from our friends... From: Lewis & Bridle 2002 Red: Pre-WMAP CMB data Blue: CMB data w/ HST Yellow: CMB data w/ HST, 2dF, BBN

11 K. Ganga – CMB Science and Observations 11 Rencontres du Vietnam /08/09 The CMB Temperature Power Spectrum Archeops/ARGO/ATCA/BAM/DASI/ DMR/FIRS/IAB/MAX(IMA)/OVRO/ Python/QMAP/Relict/Saskatoon/ South Pole/Tenerife/Toco/Viper/ White Dish/... WMAP/ Acbar/ BOOMERanG/ CBI/ VSA

12 K. Ganga – CMB Science and Observations 12 Rencontres du Vietnam /08/09 Quadrupole Scattering e-e- CMB polarization is caused by Thomson scattering of a local quadrupole (Rees, 1968). The polarized component of the CMB must be small, as it results from local temperature anisotropies.

13 K. Ganga – CMB Science and Observations 13 Rencontres du Vietnam /08/09 Polarization has been measured Lens IGW DASI, CBI, BOOMERanG and CAPMAP have all published polarization detections. DASI WMAP

14 K. Ganga – CMB Science and Observations 14 Rencontres du Vietnam /08/09 Parameters

15 K. Ganga – CMB Science and Observations 15 Rencontres du Vietnam /08/09 Can decompose Q & U into: E-modes (even-parity): (or grad) B-modes (odd-parity): (or curl) E-modes produced by all quadrupole sources (velocity gradients and gravitational waves) B-modes produced by gravitational waves and lensing of E-modes The E/B Decomposition Pure EPure B Wayne Hu

16 K. Ganga – CMB Science and Observations 16 Rencontres du Vietnam /08/09 Lensing transform E to B Converts E-modes to B-modes – Confusion limit to measuring the gravitational wave component – Interesting signal in itself, probing growth of structure from present-day to epoch of decoupling

17 K. Ganga – CMB Science and Observations 17 Rencontres du Vietnam /08/09 Inflation Constraints V E inflation ~ m pl ×r ¼ Liddle & Lyth, 2000

18 K. Ganga – CMB Science and Observations 18 Rencontres du Vietnam /08/09 Predicted Spectra TT EE Lens T/S=0.005 T/S=0.05 T/S= BB IGW

19 K. Ganga – CMB Science and Observations 19 Rencontres du Vietnam /08/09 Future Observations Lawrence, C.R., Proceedings of Science (CMB2006)

20 K. Ganga – CMB Science and Observations 20 Rencontres du Vietnam /08/09 Sensitivity to Q or U ( K s 1/2 ) HFI spec CMB BLIPCMB + Inst. BLIP No of feeds per Q (or U) Beam (arcmin) Frequen cy (GHz) The Planck HFI 50 feeds in a focal plane of ~ 1kg at 100mK Focal plane area ~ 2 square degrees Instantaneous sky coverage per polarization- sensitive frequency about: 0.1 square degrees The HFI also has channels at 100, 545 and 850 GHz that are not polarization sensitive

21 K. Ganga – CMB Science and Observations 21 Rencontres du Vietnam /08/09 Predicted Planck Measurements r=0.1,τ=0.17

22 K. Ganga – CMB Science and Observations 22 Rencontres du Vietnam /08/09 How to go deeper Planck can detect r~0.1 Planck is ~2 times BLIP Planck has ~10 detectors covering ~0.1 degree 2 per frequency Planck observes ~1 yr. In the BLIP limit, ignoring cosmic variance, Δr~ σ 2 ~(N detectors Time) -1 A future mission should: – Achieve BLIP – Observe longer (~2) ~2 for satellites John will discuss ground- based – Use many more pixels To go much deeper, we must use arrays.

23 K. Ganga – CMB Science and Observations 23 Rencontres du Vietnam /08/09 Example: EPIC J. Bock

24 K. Ganga – CMB Science and Observations 24 Rencontres du Vietnam /08/09 WMAP Foregrounds 74.3% of sky

25 K. Ganga – CMB Science and Observations 25 Rencontres du Vietnam /08/09 BOOMERanG and CBI Measurements Montroy, et al. Neither BOOMERanG nor CBI have detected any BB at the level of the EE polarization signals. This limits the foregrounds in their regions.

26 K. Ganga – CMB Science and Observations 26 Rencontres du Vietnam /08/09 Fin

27 K. Ganga – CMB Science and Observations 27 Rencontres du Vietnam /08/09 Symmetry?

28 K. Ganga – CMB Science and Observations 28 Rencontres du Vietnam /08/09 WMAP: w versus k

29 K. Ganga – CMB Science and Observations 29 Rencontres du Vietnam /08/09 WMAP: w versus m


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