1996/11/27 by Gregory S. Tucker, G. S. Tucker, Tucker, G. S. +9
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Gravity Measurements #Precipitation Measurement and Analysis #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9611225
18 pages, 3 Postscript figures, uses aasms4.sty. Accepted for publication in Ap.J.Lett
arxiv created 1996/11/27 · openalex publication_date 1996/11/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Results are reported from the first flight of a new balloon-borne instrument, BAM (Balloon-borne Anisotropy Measurement), designed to search for cosmic microwave background (CMB) anisotropy. The instrument uses a cryogenic differential Fourier transform spectrometer to obtain data in five spectral channels whose central frequencies lie in the range 3.7 cm-1 to 8.5 cm-1. The spectrometer is coupled to an off-axis prime focus telescope; the combination yields difference spectra of two regions on the sky defined by 0\fdg 7 FWHM beams separated by 3\fdg 6. Single differences obtained at ten sky positions show statistically significant fluctuations. Assuming Gaussian correlated anisotropy, for the band average 3.1 cm-1 to 9.2 cm-1, one finds ΔT/T = 3.1+3.11.1× 10-5 (90% confidence interval) for a correlation angle of 1\fdg 2. This corresponds to Qflat = 35.917.76.3 μK (1σ).