Astronomers spy distant galaxy – and it looks ‘surprisingly like our Milky Way’

The astronomers added the cosmic neighbourhood resembles a near-perfect ring of light in space. Max Planck Institute astronomers used Chile’s Atacama Large Millimeter / submillimeter Array (ALMA) telescope to find the galaxy 12 billion light years away from our planet.

Sure to its extreme distance, astronomers are viewing the galaxy when the universe was only 1.4 billion years old.

“When I first saw the reconstructed image of SPT0418-47 I could not believe it

Dr Rizzo

And galaxy SPT0418-47 is surprisingly un-chaotic, contradicting theories all galaxies in the early universe were turbulent and unstable.

The discovery shows structures in our Milky Way and other spiral galaxies when the universe was young, authors say.

Although the galaxy studied by astronomers does not appear to have spiral arms, it boasts at least two features typical of our Milky Way – a bulge and rotating disc.

A bulge is the large group of stars packed tightly around the galactic centre of spiral galaxies – seen as a white blob in the Milky Way.

This is the first time a bulge has been spotted so early in the Universe’s history, making SPT0418-47 the most distant Milky Way doppelganger.

The study’s co-author Filippo Fraternali said: “The big surprise was to find that this galaxy is actually quite similar to nearby galaxies, contrary to all expectations from the models and previous, less detailed, observations.”

The University of Groningen astronomer added the young galaxies in the early universe were still in the process of forming.

This led researchers to expect them to be chaotic and lacking the distinct structures typical of more mature galaxies like the Milky Way.

Studying distant galaxies like SPT0418-47 is considered key to understanding how galaxies evolved.

This galaxy is so distant the Universe was a mere 10 percent of its current age because its light took 12 billion years to reach our planet.

By studying the galaxy, astronomers are going back to a time when these nascent galaxies were only beginning to form.

Because these galaxies are so distant from Earth, detailed observations with even the most powerful telescopes are almost impossible as the galaxies appear so faint.

The researchers overcame this obstacle by using a nearby galaxy as a powerful magnifying glass – a technique called ‘gravitational lensing’.

This harnesses the gravitational pull from a nearby galaxy, which distorts the light from the distant galaxy, causing it to appear misshapen and magnified.

This allowed Earth-based ALMA to see into the distant past in unprecedented detail.

The gravitationally lensed, distant galaxy appears as a near-perfect ring of light around the nearby galaxy, thanks to their almost exact alignment.

The research team reconstructed the distant galaxy’s true shape and the motion of its gas from the ALMA telescope data using updated models.

Dr Rizzo said: “When I first saw the reconstructed image of SPT0418-47 I could not believe it: a treasure chest was opening.

Co-author Simona Vegetti from the Max Planck Institute, said it is the most well-ordered galaxy disc observed from the early universe.

He said: “It was puzzling. This result is quite unexpected and has important implications for how we think galaxies evolve.”

However, even though SPT0418-47 has a disc and other features similar to those of spiral galaxies we see today, they expect it to evolve into a galaxy quite distinct from ours.

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