We report on the preliminary result of a search for anisotropy in the cosmic background radiation (CBR). Our receiver operates with four equally spaced channels from 25 to 35 GHz with a beam size of ≃1.5° full width at half maximum. The system operated successfully for 500 hr at the South Pole during 1990-1991 austral summer. The data from one region, representing 25 hr after editing, are presented here. A strong signal is present in the lower- frequency channels with a spectrum unlike CBR fluctuations. The highest- frequency channel has the smallest contribution from this signal and has been used to set a 95% confidence level upper limit ΔT/T ≤ 1.4 x 10-5.
|Original language||English (US)|
|Number of pages||2|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1993|
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