MeerKAT

MeerKAT. It is a powerful radio telescope array located in the Karoo region of the Northern Cape in South Africa. Operated by the South African Radio Astronomy Observatory, it is the most sensitive telescope of its kind in the world and serves as a critical precursor instrument for the Square Kilometre Array. The array's 64 antenna dishes work together to produce high-resolution images of the radio universe, probing phenomena from cosmic magnetism to the evolution of galaxies.

Overview

The facility is situated on the SKA South Africa site, chosen for its exceptionally low radio frequency interference. This remote location in the Karoo semi-desert provides the radio-quiet environment essential for cutting-edge observations. As a pathfinder for the Square Kilometre Array, its primary role is to demonstrate technologies and develop scientific expertise ahead of the larger project's construction. The array officially began full science operations in 2018, following its inauguration by then-Deputy President of South Africa, David Mabuza.

Design and construction

The design phase involved extensive engineering work by SKA South Africa and international industrial partners. Each of the 64 antenna dishes is 13.5 meters in diameter and is equipped with state-of-the-art receiver systems. The dishes are arranged in a dense core configuration, with approximately half located within a one-kilometer diameter, while the remainder are spread out across baselines up to eight kilometers. This configuration provides exceptional sensitivity for detecting faint signals while also achieving high angular resolution. Major construction was completed between 2014 and 2018, with the first scientific image released in 2016.

Scientific capabilities and instrumentation

Its instrumentation allows it to observe across a wide frequency range, from 0.58 to 14.0 GHz. Key technological systems include the Karoo Array Telescope 7-beam L band receiver and the more recent S-band and UHF band receivers, which expand its observational versatility. The telescope's correlator, named after Ronald David Ekers, processes vast amounts of data from the antennas. These capabilities enable a diverse science program, including deep HI galaxy surveys, studies of pulsars and fast radio bursts, and observations of regions like the Galactic Centre and the Magellanic Clouds.

Key scientific results

Since commencing operations, it has produced several landmark results that have significantly advanced radio astronomy. A celebrated early image revealed intricate details of the region surrounding the supermassive black hole at the Galactic Centre, including previously unseen supernova remnants and filament structures. Its surveys, such as MIGHTEE and LADUMA, are creating unprecedented maps of neutral hydrogen in the distant universe. The telescope has also discovered numerous new pulsars and provided crucial insights into the origins of mysterious fast radio bursts, contributing data to international efforts like those of the CHIME collaboration.

Collaboration and operations

The telescope is operated by the South African Radio Astronomy Observatory on behalf of a broad international partnership. Scientific access is granted through open calls for proposals, which are evaluated by a Time Allocation Committee comprising experts from institutions like the University of Oxford, the University of Cape Town, and the Max Planck Institute for Radio Astronomy. Key operational partners include the Italian National Institute for Astrophysics and the Commonwealth Scientific and Industrial Research Organisation. The data are processed and archived at the Inter-University Institute for Data Intensive Astronomy in Cape Town, supporting a global user community.