Large-Scale Anisotropy in the 2.7-K Radiation with a Balloon-Borne Maser Radiometer at 24.5 GHz

Observations with a high-sensitivity radiometer, covering 80% of the sky, give substantially improved measurements of anisotropy in the 2.7-K radiation. The dipole effect is (Tₓ, Ty, Tz)=(-3.07±0.17, 0.67±0.09, -0.45±0.09) mK; the Earth's orbital motion through the 2.7-K radiation is detected. No statistically significant quadrupole effect is seen, and a magnitude limit of 0.19 mK is established at the 90% confidence level. Covariance analysis for angular separations between 10^∘{} and 180^∘{} gives 〈δT₁δT₂〉<0.01 (mK)².