Temperature of the diffuse background radiation at 12 centimeter wavelength

The absolute temperature T(sky) of the diffuse radiation from the sky at 12 cm wavelength has been measured at various positions along declination +38 deg. At alpha = 23 h 08 m and delta = +38 deg, T(sky) = 2.94 + or - 0.14 K, the Galactic temperature = 0.22 + or - 0.18 K, and the CMB temperature = 2.72 + or - 0.15 K. The equivalent thermodynamic temperature of the CMB is 2.79 + or - 0.15 K. The separation between the Galactic background and the CMB background is discussed. The absence of large distortions adds new questions concerning the transition from the uniform universe where the CMB originated and the present universe where large matter condensations are present. 21 references