LOFAR detection of a low-power radio halo in the galaxy cluster Abell 990
LOFAR detection of a low-power radio halo in the galaxy cluster Abell 990
Radio halos are extended ($\sim{\rm Mpc}$), steep-spectrum sources found in the central region of dynamically disturbed clusters of galaxies. Only a handful of radio halos have been reported to reside in galaxy clusters with a mass $M_{500}\lesssim5\times10^{14}\,M_\odot$. In this paper we present a LOFAR 144 MHz detection of a radio …