Multi-frequency radio-continuum study of the LMC SNR N206 (Goat's Eye) and its "zig-zag" PWN

TL;DR

This study presents new radio observations of the LMC SNR N206, revealing a unique zig-zag PWN structure, spectral indices, and magnetic properties, contributing to understanding supernova remnants and pulsar wind nebulae.

Contribution

It provides the first detailed radio analysis of N206's PWN, including spectral, polarisation, and magnetic field measurements, and reports an unusual zig-zag structure.

Findings

Spectral index of SNR: -0.60

Spectral index of PWN: -0.16

Discovery of a zig-zag structure in the PWN

Abstract

We present new radio-continuum observations of the Large Magellanic Cloud (LMC) supernova remnant (SNR) N206, which we give the name "Goat's Eye". Goat's Eye contains an interior radio structure that is likely a pulsar wind nebula (PWN), which we analyse in further detail. We use new radio observations from the Australia Telescope Compact Array (ATCA) telescope, as well as several archival radio observations, to calculate spectral indices, and find a steep spectral index for the whole SNR ($\alpha = -0.60\pm0.02$), and a flatter spectral index for the PWN ($\alpha = -0.16\pm0.03$). We also measure the polarisation and magnetic field properties of the PWN. Previously reported as a linear structure, the new observations show an unusual "zig-zag"-like structure, visible in radio-continuum total intensity, linear polarisation, and magnetic field orientations. The origin of this zig-zag structure is unclear, but we propose some origin scenarios that will require further observations to differentiate between.