First Spectroscopic Imaging Observations of the Sun at Low Radio Frequencies with the Murchison Widefield Array Prototype

TL;DR

This paper reports the first spectroscopic imaging of solar radio transients at low frequencies using the Murchison Widefield Array prototype, revealing detailed spatial, spectral, and temporal evolution of solar radio features.

Contribution

It presents pioneering low-frequency spectroscopic imaging of the Sun, demonstrating the capability to observe and analyze solar radio transients in unprecedented detail.

Findings

Detection of broadband and narrowband solar radio emission features

Observation of spatial, spectral, and temporal evolution of solar radio events

Validation of low radio frequency imaging for solar coronal diagnostics

Abstract

We present the first spectroscopic images of solar radio transients from the prototype for the Murchison Widefield Array (MWA), observed on 2010 March 27. Our observations span the instantaneous frequency band 170.9-201.6 MHz. Though our observing period is characterized as a period of `low' to `medium' activity, one broadband emission feature and numerous short-lived, narrowband, non-thermal emission features are evident. Our data represent a significant advance in low radio frequency solar imaging, enabling us to follow the spatial, spectral, and temporal evolution of events simultaneously and in unprecedented detail. The rich variety of features seen here reaffirms the coronal diagnostic capability of low radio frequency emission and provides an early glimpse of the nature of radio observations that will become available as the next generation of low frequency radio interferometers come on-line over the next few years.