Discovery of Two New Giant Radio Galaxies Offers Fresh Insights Into the Universe - Gizmodo Australia

Two giant radio galaxies have been discovered with South Africa’s powerful MeerKAT telescope, located in the Karoo region, a semi-arid area in the south west of the country.

Radio galaxies get their name from the fact that they release huge beams, or ‘jets’, of radio light.

These giant galaxies are much bigger than most of the others in the Universe and are thought to be quite rare.

Although millions of radio galaxies are known to exist, only around 800 giants have been found.

It’s also a way to understand how galaxies may continue to change and evolve – and even to work out how old radio galaxies can get.

The giant radio galaxies were spotted in new radio maps of the sky created by one of the most advanced surveys of distant galaxies.

The discovery of enormous jets and lobes in the MIGHTEE map allowed us to confidently identify the objects as giant radio galaxies.

This is tantalising evidence that a large population of faint, very extended giant radio galaxies may exist.

This may help us understand how radio galaxies become so huge and what sort of havoc supermassive black holes can wreak on their galaxies.

In some active galaxies, charged particles interact with the strong magnetic fields near the black hole and release huge beams, or ‘jets’, of radio light.

We found these giant radio galaxies in a region of sky that’s about four times the area of the full Moon.

Based on what we currently know about the density of giant radio galaxies in the sky, the probability of finding two of them in a region this size is extremely small – only 0.0003%.

So, it’s possible that giant radio galaxies – those that emit the beams, or jets of light described above – may actually be more common than we previously thought.

And that’s one question we hope this discovery can help to answer: how old are giant radio galaxies and how did they get so enormous.

This capability is what made it possible for us to detect the giant radio galaxies.

We could see features that haven’t been noticed before: large-scale radio jets coming from the central galaxies, as well as fuzzy cloud-like lobes at the end of the jets.

The fact that only very few radio galaxies are so gigantic has always been a bit of a mystery.

It is thought that the giants are the oldest radio galaxies, which have existed for long enough (several hundred million years) for their radio jets to grow outwards to these enormous sizes.

If this is true, then many more giant radio galaxies should exist than are currently known.