Extended Mosaic Observations with the Cosmic Background Imager

• Published in: The Astrophysical journal Vol. 609; no. 2; pp. 498 - 512
• Main Authors: Readhead, A. C. S, Mason, B. S, Contaldi, C. R, Pearson, T. J, Bond, J. R, Myers, S. T, Padin, S, Sievers, J. L, Cartwright, J. K, Shepherd, M. C, Pogosyan, D, Prunet, S, Altamirano, P, Bustos, R, Bronfman, L, Casassus, S, Holzapfel, W. L, May, J, Pen, U.-L, Torres, S, Udomprasert, P. S
• Format: Journal Article
• Language: English
• Published: Chicago, IL IOP Publishing 10-07-2004; University of Chicago Press; American Astronomical Society
• Subjects: Astronomy; Background radiations; Earth, ocean, space; Exact sciences and technology; Sciences of the Universe; Stellar systems. Galactic and extragalactic objects and systems. The universe; Unidentified sources and radiation outside the solar system; Cosmology; Cosmological parameter; Power spectra; Cosmic background radiation; Cosmology: Cosmological Parameters; Cosmology: Observations; Cosmology: Cosmic Microwave Background; Astrophysics
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/421105

Two years of microwave background observations with the Cosmic Background Imager (CBI) have been combined to give a sensitive, high-resolution angular power spectrum over the range 400 < l < 3500. This power spectrum has been referenced to a more accurate overall calibration derived from the Wilkinson Microwave Anisotropy Probe (WMAP). The data cover 90 deg super( 2), including three pointings targeted for deep observations. The uncertainty on the l > 2000 power previously seen with the CBI is reduced. Under the assumption that any signal in excess of the primary anisotropy is due to a secondary Sunyaev- Zeldovich anisotropy in distant galaxy clusters, we use CBI, Arcminute Cosmology Bolometer Array Receiver, and Berkeley-Illinois-Maryland Association array data to place a constraint on the present-day rms mass fluctuation on 8 h super(-1) Mpc scales, capital sigma sub(8). We present the results of a cosmological parameter analysis on the l < 2000 primary anisotropy data that show significant improvements in the parameters as compared to WMAP alone, and we explore the role of the small-scale cosmic microwave background data in breaking parameter degeneracies.