An ATCA 20cm Radio Continuum Study of the Large Magellanic Cloud

TL;DR

This study provides a detailed 1.4GHz radio continuum mosaic of the Large Magellanic Cloud, revealing its emission characteristics, star formation indicators, and spectral index variations, useful for various astrophysical analyses.

Contribution

It presents a high-resolution radio continuum map of the LMC with novel data processing techniques, enabling comprehensive studies of its emission features and star formation activity.

Findings

Diffuse and compact emission characteristics analyzed

Star formation rate inferred from thermal emission fraction

Radio spectral index varies across the LMC

Abstract

We present a mosaic image of the 1.4GHz radio continuum emission from the Large Magellanic Cloud (LMC) observed with the Australia Telescope Compact Array (ATCA) and the Parkes Telescope. The mosaic covers 10.8 x 12.3 square degrees with an angular resolution of 40", corresponding to a spatial scale of 10pc in the LMC. The final image is suitable for studying emission on all scales between 40" and the surveyed area. In this paper, we discuss i) the characteristics of the LMC's diffuse and compact radio continuum emission, ii) the fraction of the emission produced by thermal processes and the implied star formation rate in the LMC, and iii) variations in the radio spectral index across the LMC. Two non-standard reduction techniques that we used to process the ATCA visibility data may be of interest for future wide-field radio continuum surveys. The data are open to the astronomical community and should be a rich resource for studies of individual objects such as supernova remnants, HII regions and planetary nebulae, as well as extended features such as the diffuse emission from synchrotron radiation.