Measurements of Anisotropy in the Cosmic Microwave Background Radiation at 0[fdg]5 Scales near the Stars HR 5127 and φ Herculis

We present measurements of cosmic microwave background (CMB) anisotropy near the stars HR5127 and Phi Herculis from the fifth flight of the Millimeter-wave Anisotropy eXperiment (MAX). We scanned 8arcdeg strips of the sky with an approximately Gaussian 0fdg5 FWHM beam and a 1fdg4 peak to peak sinusoidal chop. The instrument has four frequency bands centered at 3.5, 6, 9, and 14~cm$^{-1}$. The IRAS 100~micron map predicts that these two region have low interstellar dust contrast. The HR5127 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$^{-1}$ 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 HR5127 structure and the atmosphere independent Phi Herculis structure are attributed to CMB anisotropy, then we find $Delta T/T = langlefrac{l(l+1)C_l}{2pi} angle^{1/2} = 1.2^{+0.4}_{-0.3} imes 10^{-5}$ for HR5127 and $1.9^{+0.7}_{-0.4} imes 10^{-5}$ for Phi Herculis in the flat band approximation. The upper and lower limits represent a 68% confidence interval added in quadrature with a 10% calibration uncertainty.Comment: 17 pages, 2 Postscript figures, uses aasms4.st