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Session 112 - Early Universe & the CMB.
Oral session, Saturday, January 10
International Ballroom Center,
We report the observations made by the Python microwave background experiment in its fourth season of operation at the Amundsen-Scott South Pole Station in Antarctica. For this season the Python telescope was fitted with a new HEMT amplifier-based radiometer, yielding sensativity to the microwave sky from 37-45 GHz in two frequency bands for each pixel in a 1 \times 2 array, each pixel with a one degree beam on the sky. The modified instrument re-observed fields which had been measured to high signal-to-noise in previous seasons with the Python 90 GHz bolometric receiver. For a portion of the new observations, the previous sampling pattern was closely replicated, allowing a simple \chi^2 comparison of these parts of the two datasets. On these fields both the 40 GHz data and the 90 GHz data detect signal at high significance. They are consistent with each other assuming a common, single-component source with spectral index in temperature of \beta = -0.38^+0.95_-0.75. Constraints on multicomponent (CMB + foreground) models are discussed. Results from more general (although model-dependant) comparisons based on joint-likelihood ratios, and using both entire datasets, are also presented.
The author(s) of this abstract have provided an email address for comments about the abstract: john@landru.uchicago.edu