Cmb Power Spectrum from the Complete Acbar Data Set

In this paper, we present results from the complete set of cosmic microwave background (CMB) radiation temperature anisotropy observations made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR) operating at 150GHz. We include new data from the final 2005 observing season, expanding the number of detector-hours by 210% and the sky coverage by 490% over that used for the previous ACBAR release. As a result, the band-power uncertainties have been reduced by more than a factor of two on angular scales encompassing the third to fifth acoustic peaks as well as the damping tail of the CMB power spectrum. The calibration uncertainty has been reduced from 6% to 2.2% in temperature through a direct comparison of the CMB anisotropy measured by ACBAR with that of the dipole-calibrated WMAP3 experiment. The measured power spectrum is consistent with a spatially flat, ΛCDM cosmological model. We see evidence for weak gravitational lensing of the CMB at > 3σ significance by comparing the likelihood for the best-fit lensed/unlensed models to the ACBAR+WMAP3 data. On fine angular scales, there is weak evidence (1.7σ) for excess power above the level expected from primary anisotropies. The source of this power cannot be constrained by the ACBAR 150GHz observations alone; however, if it is the same signal seen at 30GHz by the CBI and BIMA experiments, then it has a spectrum consistent with the Sunyaev-Zel’dovich effect. Subject headings: cosmic microwave background — cosmology: observations