Giant radio galaxies (GRGs) are massive, with plasma jets powered by supermassive black holes at their centers, stretching millions of light-years. They were once considered rare, but new radio telescopes like South Africa’s MeerKAT have changed that idea.
GRG discoveries have increased dramatically in the past five years thanks to powerful new telescopes like MeerKAT.
Astronomers using the MeerKAT telescope spotted a giant radio galaxy with plasma jets 32 times the size of our Milky Way, spanning 3.3 million light-years. Due to the difficulty in understanding its physics, it is nicknamed Inkathazo, meaning ‘trouble’ in Xhosa and Zulu languages.
This discovery explains the origin and evolution of some of the universe’s largest structures. Kathleen Charlton, a Master’s student at the University of Cape Town, noted that Inkathazo’s plasma jets have an unusual shape, with one bent instead of extending straight.
Inkathazo is located in the center of a galaxy cluster, which should make it hard for plasma jets to grow so large.
K.K.L Charlton (UCT), MeerKAT, HSC, CARTA, IDIA
Dr. Kshitij Thorat from the University of Pretoria stated that this raises questions about how the environment affects the formation and growth of these giant galaxies.
Researchers used MeerKAT’s powerful capabilities to create detailed age maps of the plasma in the GRG, providing insights into the physical processes involved. The results showed complex behaviors in Inkathazo’s jets, with some electrons getting unexpected energy boosts, possibly from collisions with hot gas between galaxies.
Dr. Thorat said the findings challenge existing models and suggest we don’t fully understand the complex plasma physics in these extreme galaxies.
Most known GRGs have been found in the northern sky with European telescopes, while the southern sky is less explored. However, Inkathazo is the third GRG found in a small area called ‘COSMOS’ by astronomers.
The ‘MIGHTEE’ collaboration, an international team, used the MeerKAT telescope to observe COSMOS and discovered two GRGs in 2021. Inkathazo was found later in follow-up observations with MeerKAT, operated by the South African Radio Astronomy Observatory.
Dr. Jacinta Delhaize from the University of Cape Town said that finding three GRGs in a small sky patch suggests many undiscovered GRGs in the southern sky. MeerKAT is powerful and well-placed to uncover them.
MeerKAT is a precursor to the Square Kilometre Array (SKA), set to begin operations at the end of this decade. It offers great sensitivity and resolution, enabling discoveries like Inkathazo. Dr. Delhaize said we are entering an exciting era of radio astronomy, and the SKA will push boundaries even further, helping solve mysteries of giant radio galaxies.
Journal Reference:
- K K L Charlton, J Delhaize, et al. A spatially resolved spectral analysis of giant radio galaxies with MeerKAT. Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/stae2543
Source: Tech Explorist
