First Look Murchison Widefield Array observations of Abell 3667

TL;DR

This paper presents the first low-frequency radio observations of the Abell 3667 galaxy cluster's radio relics using the Murchison Widefield Array, revealing spectral properties and spatial variations.

Contribution

First low-frequency observations of Abell 3667's radio relics with the MWA, providing flux estimates and spectral index variations.

Findings

Detected radio relics in Abell 3667 at 120-226 MHz

Measured spectral indices of -0.9 for the relics

Resolved spatial spectral index variation from -1.7 to -0.4

Abstract

The Murchison Widefield Array (MWA) is a new low frequency interferometric radio telescope, operating in the remote Murchison Radio Observatory in Western Australia. In this paper we present the first MWA observations of the well known radio relics in Abell 3667 (A3667) between 120 and 226 MHz. We clearly detect the radio relics in A3667 and present flux estimates and spectral indices for these features. The average spectral index of the north-west (NW) and south-east (SE) relics is -0.9 +/- 0.1 between 120 and 1400 MHz. We are able to resolve spatial variation in the spectral index of the NW relic from -1.7 to -0.4, which is consistent with results found at higher frequencies.