Unveiling the Origin of Peculiar Diffuse Radio Emission in A1351

Abstract

Abell 1351 (A1351) is a massive merging cluster that hosts a giant radio halo and a bright radio edge blended in the halo. In this paper, we present the first ever spectral analysis of this cluster using GMRT 610 MHz and VLA 1.4 GHz archival data and discuss the radio edge property. Using Chandra data, we report the first tentative detection of shock front at the location of the edge in A1351 with discontinuities in both X-ray surface brightness and temperature. Our analysis strengthens the previous claim of the detected “edge” being a high luminosity radio relic. The radio relic has an integrated spectral index α = − 1.63 ± 0.33 and radio power P 1.4 GHz = 4.46 ±0.61 × 1024 W Hz−1 with a largest linear size of 570 kpc. The radio spectral index map shows steepening in the shock downstream region. Our analysis favors the scenario where the diffusive shock acceleration of particles is responsible for the origin of the radio relic in the presence of a strong magnetic field. We have also estimated the magnetic field at the relic location assuming equipartition condition.