High Resolution Observations of the CMB with the CBI Interferometer

XVIIIth IAP Colloquium - July 1 2002

Carlo Contaldi

CITA

T. Readhead (Caltech)

T. Pearson (Caltech)

S. Myers (NRAO)

B. Mason (Caltech/NRAO)

J. Sievers (Caltech)

J. Cartwright (Caltech)

P. Udompraesert (Caltech)

M. Shepherd (Caltech)

A. Farmer (Caltech)

S. Padin (Caltech)

J. R. Bond (CITA)

C. Contaldi (CITA)

D. Pogosyan (U of Alberta)

U.-L. Pen (CITA)

M. Ruetalo (CITA/UofT)

P. Zhang (CITA/UofT)

J. Wadsley (McMaster)

S. Prunet (IAP)

•13 elements

•0.90 m dishes

•45’ FWHM

•78 baselines

•10 frequency channels 26-36 GHz

l~200

The Cosmic Background Imager

> 5000m Atacama Plateau Chile

10-channel single pointing uv-coverage 26-36 GHz

single pointing uv-coverage

mosaic pointings

CBI Power spectrum extraction

•Visibilities ‘gridded’ in uv plane [Myers at al. 2002].

•Quadratic estimator solves for the ML band powers

•6x7 field mosaic; ~10 hrs. 16 processor GS320 cluster @ CITA

•Foreground templates projected out using known positions

Sj = QijVi Cij = hSiS?j i

CB =P

` `W`

BC̀

C Tot = C N+C CMB+C src+C res

CBI Mosaic Power Spectrum

•3 6x7 field mosaics

•~ 145’x165’ each

•~ 40 sq. deg.

[Pearson et al. 2002]

“Silk” damping

eà (`=̀D)mD

Mosaic Window Functions

! c ! b ÒË Òtot ns üc

Weak

Weak + Flat +LSS

Flat + LSS + HST-h

0:17+0:08à0:06 0:022+0:015à0:009 0:40+0:25à0:27 0:99+0:12à0:12 1:05+0:09à0:08 0:24+0:18à0:17

0:13+0:02à0:01 0:025+0:010à0:008 0:64+0:10à0:13 1:01+0:10à0:07 0:15+0:17à0:11

0:13+0:02à0:01 0:027+0:009à0:008 0:68+0:05à0:07 1:04+0:08à0:07 0:19+0:15à0:13

CBI+DMR[Sievers et al. 2002]

CBI Deep Field

Power Spectrum

BOOMERanG2001

[Mason et al. 2002]

CBI High-l Excess

Significant power above l=2000. 3.5 inconsistent with zero and 3.1 inconsistent with best-fit model.

Secondary Anisotropies from Sunyaev-Zeldovich Effect?

Amplitude ~ 4.5 higher than expected signal from residual low-flux sources

Estimate includes 50% error in residual source flux.

Raw map

Total Signal

CMB + ?

OVRO & NVSS Source residuals

SZE Angular Power Spectrum

•Smooth Particle Hydrodynamics (5123) [Wadsley et al. 2002]

•Moving Mesh Hydrodynamics (5123) [Pen 1998]

•143 Mpc 8=1.0

•200 Mpc 8=1.0

•200 Mpc 8=0.9

•400 Mpc 8=0.9

[Bond et al. 2002]

Dawson et al. 2002

Simulation of Deep Observations by the CBI

Input SZ map Reconstructed Signal

Bandpower Estimation with a SZ Foreground

CBI Pipeline recovers input SZE signal at observed amplitudes

Non-Gaussian scatter from the SZ signal is significant in the high-l band given the small areas observed

Single Deep Field (08h) simulated observation

Flat

HST-h

Priors

LSS parameters from CMB and other

Cosmological Surveys

•The CBI observations l<2000 give consistent parameters with those of previous experiments on larger angular scales

•Measurement of the damping tail at l>1000

•6’ scales probing ~1014MO seeds of clusters

•High-l excess; Simulations show the Sunyaev-Zeldovich Effect fits the observed power for 8~1.0. This is in the high-end of the range allowed by CMB and LSS surveys

•SZE: high-accuracy determination of 8. Break 8-ΩM degeneracy ΩΛ

•Follow-up on excess

•Extended mosaic data ~ 80 sq. deg.

•Improved hydrodynamical simulations

Summary

•Optimally configured for resolution of peaks

•Polarization upgrade nearly complete

•Calibration runs in August

Polarization Observations

2002/3