Anisotropy in the Microwave Sky: Results from the First Flight of BAM
Abstract
Results are reported from the first flight of a new balloonborne instrument, BAM (Balloonborne 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 offaxis 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 $\Delta T/T = 3.1^{+3.1}_{1.1}\times 10^{5}$ (90% confidence interval) for a correlation angle of 1\fdg 2. This corresponds to $Q_{flat} = 35.9^{17.7}_{6.3} \mu K$ (1\sigma).
 Publication:

arXiv eprints
 Pub Date:
 November 1996
 DOI:
 10.48550/arXiv.astroph/9611225
 arXiv:
 arXiv:astroph/9611225
 Bibcode:
 1996astro.ph.11225T
 Keywords:

 Astrophysics
 EPrint:
 18 pages, 3 Postscript figures, uses aasms4.sty. Accepted for publication in Ap.J.Lett