The 1.28 GHz MeerKAT Galactic Center Mosaic

TL;DR

This paper presents a high-resolution, sensitive radio survey of the Galactic Center using MeerKAT, revealing new features such as supernova remnants, non-thermal filaments, and detailed structures of key regions.

Contribution

It provides the first high-resolution, wide-area radio mosaic of the Galactic Center at 1.28 GHz, uncovering new astrophysical features and structures.

Findings

Discovery of new supernova remnant candidates

Identification of numerous non-thermal filament complexes

Enhanced imaging of the Radio Arc Bubble, Sgr A, and Sgr B regions

Abstract

The inner $\sim$200 pc region of the Galaxy contains a 4 million M$_{\odot}$ supermassive black hole (SMBH), significant quantities of molecular gas, and star formation and cosmic ray energy densities that are roughly two orders of magnitude higher than the corresponding levels in the Galactic disk. At a distance of only 8.2 kpc, the region presents astronomers with a unique opportunity to study a diverse range of energetic astrophysical phenomena, from stellar objects in extreme environments, to the SMBH and star-formation driven feedback processes that are known to influence the evolution of galaxies as a whole. We present a new survey of the Galactic center conducted with the South African MeerKAT radio telescope. Radio imaging offers a view that is unaffected by the large quantities of dust that obscure the region at other wavelengths, and a scene of striking complexity is revealed. We produce total intensity and spectral index mosaics of the region from 20 pointings (144 hours on-target in total), covering 6.5 square degrees with an angular resolution of 4$"$,at a central frequency of 1.28 GHz. Many new features are revealed for the first time due to a combination of MeerKAT's high sensitivity, exceptional $u,v$-plane coverage, and geographical vantage point. We highlight some initial survey results, including new supernova remnant candidates, many new non-thermal filament complexes, and enhanced views of the Radio Arc Bubble, Sgr A and Sgr B regions. This project is a SARAO public legacy survey, and the image products are made available with this article.