CMB Science and Observations K Ganga CMB Science

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

The CMB ● ● ● K. Ganga – CMB Science and Observations 2 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) Rencontres du Vietnam - 2006/08/09

The CMB again. . . Thanks to A. Taylor Recombination Horizon ~1 o Plasma Gravitational lensing T=2. 73 K Reionisation Observer K. Ganga – CMB Science and Observations 3 z =1000 z = infinity Rencontres du Vietnam - 2006/08/09

T on super-horizon scales (>1 o) • Sachs-Wolfe Effect: Gravitational redshift due to photons climbing out of potential wells, A. Taylor K. Ganga – CMB Science and Observations 4 Rencontres du Vietnam - 2006/08/09

Acoustic Oscillations K. Ganga – CMB Science and Observations 5 Rencontres du Vietnam - 2006/08/09

Measuring Curvature Flat Closed 1 2 B. Crill Open 3 J. Ruhl Acoustic horizon (same for all) vs tdec K. Ganga – CMB Science and Observations 6 Rencontres du Vietnam - 2006/08/09

Baryons change the “effective mass” W. Hu K. Ganga – CMB Science and Observations 7 Rencontres du Vietnam - 2006/08/09

How Parameters are Fit Angular spectrum varies mostly with 8 b cdm H 0, ns 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. K. Ganga – CMB Science and Observations 8 Rencontres du Vietnam - 2006/08/09

'Degeneracies' require other data Simulated “Pretty flat” models lpeak 200 0 -1/2 tot = 1 K. Ganga – CMB Science and Observations 9 Rencontres du Vietnam - 2006/08/09

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, 2 d. F, BBN K. Ganga – CMB Science and Observations 10 Rencontres du Vietnam - 2006/08/09

The CMB Temperature Power Spectrum WMAP/ Acbar/ BOOMERan. G/ CBI/ VSA Archeops/ARGO/ATCA/BAM/DASI/ DMR/FIRS/IAB/MAX(IMA)/OVRO/ Python/QMAP/Relict/Saskatoon/ South Pole/Tenerife/Toco/Viper/ White Dish/. . . K. Ganga – CMB Science and Observations 11 Rencontres du Vietnam - 2006/08/09

Quadrupole Scattering e- K. Ganga – CMB Science and Observations 12 Rencontres du Vietnam - 2006/08/09

Polarization has been measured DASI, CBI, BOOMERan. G and CAPMAP have all published polarization detections. WMAP DASI Lens IGW K. Ganga – CMB Science and Observations 13 Rencontres du Vietnam - 2006/08/09

Parameters K. Ganga – CMB Science and Observations 14 Rencontres du Vietnam - 2006/08/09

The E/B Decomposition 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 K. Ganga – CMB Science and Observations 15 Rencontres du Vietnam - 2006/08/09

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 K. Ganga – CMB Science and Observations 16 Rencontres du Vietnam - 2006/08/09

Inflation Constraints V Einflation ~ mpl×r¼ Liddle & Lyth, 2000 K. Ganga – CMB Science and Observations 17 Rencontres du Vietnam - 2006/08/09

Predicted Spectra TT EE BB IGW Lens T/S=0. 05 T/S=0. 0005 K. Ganga – CMB Science and Observations 18 Rencontres du Vietnam - 2006/08/09

Future Observations Lawrence, C. R. , Proceedings of Science (CMB 2006) K. Ganga – CMB Science and Observations 19 Rencontres du Vietnam - 2006/08/09

The Planck HFI • 50 feeds in a focal plane of ~ 1 kg at 100 m. K • Focal plane area ~ 2 square degrees • Instantaneous sky coverage per polarizationsensitive frequency about: 0. 1 square degrees The HFI also has channels at 100, 545 and 850 GHz that are not polarization sensitive K. Ganga – CMB Science and Observations 20 Rencontres du Vietnam - 2006/08/09

Predicted Planck Measurements r=0. 1, τ=0. 17 K. Ganga – CMB Science and Observations 21 Rencontres du Vietnam - 2006/08/09

How to go deeper ● Planck can detect r~0. 1 ● Planck is ~2 times BLIP – Achieve BLIP Planck has ~10 detectors covering ~0. 1 degree 2 per frequency – Observe longer (~2) ● ● ● Planck observes ~1 yr. – In the BLIP limit, ignoring cosmic variance, Δr~ σ2 ~(Ndetectors • Time)-1 K. Ganga – CMB Science and Observations A future mission should: ● 22 ~2 for satellites John will discuss groundbased Use many more pixels To go much deeper, we must use arrays. Rencontres du Vietnam - 2006/08/09

Example: EPIC J. Bock K. Ganga – CMB Science and Observations 23 Rencontres du Vietnam - 2006/08/09

WMAP Foregrounds 74. 3% of sky K. Ganga – CMB Science and Observations 24 Rencontres du Vietnam - 2006/08/09

BOOMERan. G and CBI Measurements Neither BOOMERan. G nor CBI have detected any BB at the level of the EE polarization signals. This limits the foregrounds in their regions. Montroy, et al. K. Ganga – CMB Science and Observations 25 Rencontres du Vietnam - 2006/08/09