Scientists discover rare radio halo from distant galaxy cluster

A TEAM of South African scientists have made a groundbreaking discovery using the MeerKAT radio telescope, locating a rare and exceedingly faint radio glow emanating from a colossal cluster of galaxies positioned approximately 7 billion light-years away.

- STAFF REPORTER

MEERKAT-discovered radio halo (pink) and hot X-ray gas (blue) between the galaxies (orange) that make up the massive galaxy cluster SPT-CLJ2337-5942.

This type of glow — called an ultra-steep-spectrum radio halo — is the most distant one ever found.

Galaxy clusters are the largest objects in the universe, held together by gravity, containing thousands of galaxies and enormous amounts of hot gas. The newly discovered radio glow sits at the centre of the cluster SPT-CLJ2337-5942, which has a mass of roughly a quadrillion times that of the Sun (a million billion).

The discovery, led by Isaac Magolego, a PhD student at the University of the Witwatersrand (Wits), supervised by Professors Roger Deane and Kshitij Thorat, from Wits and the University of Pretoria, has been accepted for publication in Monthly Notices of the Royal Astronomical Society: Letters. The student project is supported by the South African Radio Astronomy Observatory (SARAO). “At first, I thought this was a normal radio halo,’ said Magolego.