The brightness temperature of the south celestial pole and the temperature of the cosmic background radiation measured at 36.6 and 12 centimeter wavelength

Abstract

The absolute temperature of the sky around the south celestial pole has been measured at v = 0.82 GHz (λ = 36.6 cm) and v = 2.5 GHz (λ = 12 cm) during an observing campaign from the Amundsen Scott Base at the South Pole in 1989 December. The antennas had an angular resolution of 18^deg^ x 23^deg^. The measured temperatures of the sky have been used to determine the temperature of the cosmic background radiation in a frequency region where large deviations from a pure Planckian spectrum are expected. The results at 2.5 GHz ({TAU}_sky_=2.58+/-0.34 K, T^th^_CBR_=2.50+/-0.34K) are fully consistent with the results of previous observations at the same frequency. At 0.82 GHz an undesired level of the system attenuation gave large error bars ({TAU}_sky_=5.7+/-1.6 K, {TAU}^th^_CBR_=2.7+/-1.6 K). In spite of that limitation we report the 0.82 GHz results because no data at the same or nearby frequencies can be found in the literature.