Diffuse radio emission from the coma cluster of galaxies at decametre wavelengths

Abstract

We have observed the region of the Coma cluster at 34.5 MHz with a resolution of 26 arcmin × 40 arcmin. A map of the diffuse halo (Coma C) is presented. The size of the halo is found to be 54 arcmin × 30 arcmin. The position angle is 50° ± 10° and the integrated flux is 60 ± 11 Jy. We have also found an extended source to the south of Coma A. The measured half-power widths of this source are 30 arcmin × 40 arcmin. The position angle is 135° and the integrated flux is ~ 15 Jy at 34.5 MHz. The spectral index in the frequency range 408 to 34.5 MHz is -1.0. It is suggested that this source also belongs to the Coma cluster.