Unveiling The Origin of Peculiar Diffuse Radio Emission in Abell 1351

TL;DR

This study analyzes the diffuse radio emission in Abell 1351, revealing a radio relic likely caused by shock acceleration, supported by spectral, X-ray, and magnetic field data, marking the first detailed spectral analysis of this cluster.

Contribution

First spectral analysis of Abell 1351's radio relic using GMRT and VLA data, linking shock fronts with radio emission and magnetic fields.

Findings

Detection of a shock front at the radio edge in X-ray data.

Radio relic exhibits a steep spectral index of -1.63.

Magnetic field estimated assuming equipartition.

Abstract

Abell 1351 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 \textit{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 $\alpha = -1.63 \pm 0.33$ and radio power $P_{1.4 \mathrm{\ GHz}} = 4.46 \pm 0.61\times10^{24}$ W $Hz^{-1}$ with a largest Linear Size (LLS) of 570 kpc. The radio spectral index map shows steepening in the shock downstream region. Our analysis favours the scenario where the Diffusive Shock Acceleration (DSA) of particles is responsible for the origin of the radio relic in the presence of strong magnetic field. We have also estimated the magnetic field at the relic location assuming equipartition condition.