The absolute temperature of the sky and the temperature of the cosmic background radiation at 600 MHz

Abstract

The absolute temperature of the sky at σ = 46.5^deg^ has been measured at 600 MHz (50 cm wavelength) using a differential radiometer and a cold calibrator at liquid helium temperature. To separate the cosmic background radiation (CBR) from the remaining components of the sky temperature, observations at other frequencies, now underway, are necessary. A preliminary estimate of the CBR temperature at 600 MHz made using our data of T_sky_t at 600 MHz and maps of the sky at 408 MHz already in the literature gives T_cbr_ = (3.0 +/- 1.2) K, in good agreement with previous measurements at nearby frequencies.