Measurements of anisotropy in the cosmic microwave backgroundradiation at 0 degrees.5 scales near the stars HR 5127 and phiHerculis

• Published in: The Astrophysical journal 1995-12, Vol.468 (2pt2)
• Main Authors: Tanaka, S.T., Clapp, A.C., Devlin, M.J., Figueiredo, N., Gundersen, J.O., Hanany, S., Hristov, V.V., Lange, A.E., Lim, M.A., Lubin, P.M., Meinhold, P.R., Richards, P.L., Smoot, G.F., Staren, J.
• Format: Article
• Language: English
• Subjects: AMPLITUDES; ANISOTROPY; CALIBRATION; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DUSTS; QUADRATURES; RADIATIONS; RELICT RADIATION; SKY; STARS
• ISSN: 0004-637X; 1538-4357

We present measurements of cosmic microwave background (CMB) anisotropy near the stars HR 5127 and phi Herculis from the fifth flight of the Millimeter-wave Anisotropy eXperiment (MAX). We scanned 8 degrees strips of the sky with an approximately Gaussian 0.5 degrees FWHM beam and a 1.4 degrees peak to peak sinusoidal chop. The instrument has four frequency bands centered at 3.5, 6, 9, and 14 cm(-1). The IRAS 100 mu mmap predicts that these two regions have low interstellar dust contrast. The HR 5127 data are consistent with CMB anisotropy. The phi Herculis data, which were measured at lower flight altitudes, show time variability at 9 and 14 cm(-1), which we believe to be due to atmospheric emission. However, the phi Herculis data at 3.5 and 6 cm-l are essentially independent of this atmospheric contribution and are consistent with CMB anisotropy. Confusion from Galactic foregrounds is unlikely based on the spectrum and amplitude of the structure at these frequencies. If the observed HR 5127 structure and the atmosphere-independent phi Herculis structure are attributed to CMB anisotropy, then we find Delta T/T = [I(I + 1)C-1/2 pi](1/2) =1.2(-0.3)(+0.4) x 10(-5) for HR 5127 and 1.9(-0.4)(+0.7) x 10(-5) for phi Herculis in the flat band approximation. The upper and lower limits represent a 68 percent confidence interval added in quadrature with a 10 percent calibration uncertainty.