The Second Measurement of Anisotropy in the Cosmic Microwave Background Radiation at 0[fdg]5 Scales near the Star μ Pegasi

Abstract

During the fifth flight of the Microwave Anisotropy Experiment (MAX5), we\nrevisited a region with significant dust emission near the star Mu Pegasi. A\n3.5 cm$^{-1}$ low frequency channel has been added since the previous\nmeasurement (\\cite{mei93a}). The data in each channel clearly show structure\ncorrelated with IRAS 100 \\micron\\ dust emission. The spectrum of the structure\nin the 6, 9 and 14 cm$^{-1}$ channels is described by\n$I_{\\nu}\\propto\\nu^{\\beta}B_{\\nu}(T_{dust})$, where $\\beta$ = 1.3 and\n$T_{dust}$ = 19~K and $B_{\\nu}$ is the Planck function. However, this model\npredicts a smaller amplitude in the 3.5 cm$^{-1}$ band than is observed.\nConsidering only linear combinations of the data independent of the best fit\nforeground spectrum for the three lower channels, we find an upper limit to\nCMBR fluctuations of $\\Delta T/T = \\langle\n\\frac{C_l~l(l+1)}{2\\pi}\\rangle^{\\frac{1}{2}} \\leq 1.3\\times 10^{-5}$ at the\n95\\% confidence level. The result is for a flat band power spectrum and does\nnot include a 10\\% uncertainty in calibration. It is consistent with our\nprevious observation in the region.\n