Page 25 - EngineerIt June 2021

SPACE SCIENCES

MeerKAT's stunning image reveals

cosmic threads, ribbons and rings

The Fanaroff-Riley Type I radio galaxy
IC 4296 dominates this spectacular
vista, wider than the full moon on
the sky. MeerKAT radio data are
represented in red/orange hues in this
composite view. The visible light image
from the SuperCOSMOS Sky Survey
shows the central giant elliptical
galaxy, as well as numerous unrelated
galaxies and foreground stars in the
Milky Way. Credit: SARAO, SSS, S.
Dagnello and W. Cotton (NRAO/AUI/
NSF). Adapted from J. Condon et
al., “Threads, Ribbons, and Rings
in the Radio Galaxy IC 4296” (The
Astrophysical Journal, in press).

A new study using the MeerKAT radio telescope has produced a striking image showing a
combination of cosmic features never before seen, revealing unexpected details of the inner
workings of enormous radio galaxies.

t the centre of the giant elliptical galaxy IC 4296 is a rotating black hole with a mass “smoke rings” visible in the left radio lobe.
of a billion suns. Energy released by matter falling onto the black hole generates Jim Condon of the US National
Atwo opposing radio jets containing magnetic fields and relativistic electrons. After Radio Astronomy Observatory – lead
travelling through intergalactic space at the speed of light for 160 million years, these radio author of the study just accepted for
waves were detected by the South African Radio Astronomy Observatory’s MeerKAT publication in The Astrophysical Journal
telescope, located in the Karoo region of the Northern Cape province of South Africa. that summarizes this research done by
The bright spines of the initially straight jets become unstable just outside the galaxy, a US-South African team – says that
where some of the electrons escape to create several faint radio “threads” below IC 4296. “only MeerKAT’s unique combination
Between the bright jets and the outer lobes are smooth “ribbons” filling channels excavated of sensitivity, angular resolution, and
from the surrounding gas by defunct jets from an earlier period of activity. The ribbons are dynamic range allowed the discovery of
eventually stopped by intergalactic gas, nearly a million light-years from the central galaxy these threads, ribbons, and rings” in this
(a distance equal to 10 times the diameter of our Milky Way home galaxy), and form the previously well-studied galaxy.

EngineerIT | June 2021 | 23