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 δ = 46°.5 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 Tsky at 600 MHz and maps of the sky at 408 MHz already in the literature gives Tcbr = (3.0 ± 1.2) K, in good agreement with previous measurements at nearby frequencies.