A High Resolution Measurement of Temperature Anisotropies in the Cosmic Microwave Background Radiation with the Complete ACBAR Data Set

The Arcminute Cosmology Bolometer Array Receiver (ACBAR) is a 16-element spiderweb bolometer array operating at 150 GHz. Mounted on the 2.1m Viper telescope, ACBAR has dedicated four years to cosmic microwave background (CMB) observations at the South Pole. We describe the focal plane reconstruction and performance of ACBAR for the 2005 austral winter. We present a new CMB temperature anisotropy power spectrum for the complete ACBAR data set. The addition of data from the 2005 observing season expands the data set by 210%; and the sky coverage by 490%; over the previous ACBAR releases. The expanded data set allows us to derive a new set of band-power measurements with finer ℓ-resolution and dramatically smaller uncertainties. In particular, the band-power uncertainties have been reduced by more than a factor of two on angular scales encompassing the third and fourth acoustic peaks and the damping tail of the CMB power spectrum. The calibration has been significantly improved from 6%; to 2.2%; in temperature by using a direct comparison between CMB anisotropy maps measured by WMAP3 and ACBAR to transfer the WMAP dipole-based calibration to ACBAR. The resulting power spectrum is consistent with theoretical predications for a spatially flat, dark energy-dominated Lambda CDM cosmology