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Galaxies like the Milky Way are found in deep space puzzles for astronomers



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SPT0418-47 is attracted to the lens by another galaxy, giving it the image of the Devil’s Eye Sauron to our telescope.

ALMA (ESO / NAOJ / NRAO) / Rizzo et al.

Twelve billion years ago, when all space just a fledgling universe, a young galaxy reminiscent of the Milky Way galaxy bursting with life deep in the universe. Astronomers often think of this early universe as a chaotic, inhospitable environment where galaxies are unstable and violent. The new study suggests those assumptions may be inaccurate, providing new insight into how galaxies form.

In a new study, published in the journal Nature on Wednesday, observations made by Chile’s Atacama Large Millimeter / submillimeter Array (ALMA) SPT – S J041839–4751.9, or SPT0418-47 for short, suggests that the infant galaxy has features similar to that of our own more mature Milky Way. Light from the galaxy took 12 billion years to reach us. That means astronomers are looking back in time in a galaxy that formed less than 1.5 billion years after the universe was born.

Previous models and observations have led astronomers to hypothesize that the post-universe period was chaotic. The early galaxies were capable of smashing together and merging to form large, messy star clumps. They should not settle into neat, flat discs. But SPT0418-47 does, and it is a rather surprising thing that upsets some of our beliefs about early cosmic activities in the universe.

“This result represents a breakthrough in the field of galaxy formation, suggesting that the structures we observe in nearby spiral galaxies and in our Milky Way have since 12 billion years ago, “said Francesca Rizzo, a PhD in astronomy. student at Germany’s Max Planck Institute of Astrophysics and the first author of the study, said in a statement.

Since the SPT0418-47 is so far away, it is difficult to locate in the sky because its light is too dim. To find and characterize the SPT0418-47, the team took advantage of a phenomenon known as the “gravitational lens”. Light from distant galaxies does not travel in a straight line to Earth – it is affected by the effects of gravity on its way here. Nearby galaxies distort and reshape light from farther galaxies as it travels to our telescope.

But lenses can aid detection. Using the ALMA telescope and technique, the researchers were able to magnify light from SPT0418-47 and increase the resolution to observe the characteristics of the young galaxy. The lens effect means that the image obtained by ALMA shows the SPT0418-47 as a ring of the ferocious, fiery Sauron’s eyes, a perfect circle of light containing hundreds of thousands of stars.

Using computer modeling techniques, the team captured the round, gravitational lens images of SPT0418-47 and reconstructed what the galaxy would look like if our telescopes were strong enough to see for yourself that distance (as the video below illustrates). The model reshaped the galaxy in a surprising way.

Rizzo said: “The first time I saw reconstructed images of SPT0418-47, I couldn’t believe it. “A chest has been opened.”

Reconstruction shows that SPT0418-47 does not quite have the large spiral arms that we normally see in the Milky Way, but it has a giant disc and a bulge in the center, reminiscent of the home galaxy. our. The Southern European Observatory claims it to be a Milky Way.

“It looks less like a look and resembles a smaller me,” said Sarah Martell, an astrophysicist at the University of New South Wales, who is not affiliated with the study. “It’s only 25% of the mass of the Milky Way, and half the size.”

But what it lacks in stature it makes up for in star power. The star-forming rate of the galaxy is equivalent to our solar mass of 350, which Martell calls “gigantic”. For comparison, she notes, the Milky Way’s star formation rate is only 1.6 solar masses per year. Simona Vegetti notes that the rate of star formation is “rather confusing”, because it denotes the galaxy as the site of high-energy processes. Perhaps, this would lead to more confusion, but SPT0418-47 remained calm and calm even with all that activity.

Young galaxies will not develop into Milky Way spiral galaxies like the ones we are familiar with today. Instead, researchers believe it will become an elliptical galaxy like Messier 87, where the first images of a black hole were taken. Such fate will not happen for millions of years. However, when the European Southern Observatory’s Ultra-Large Telescope comes into play in 2025, it’s likely that astronomers will find more of these more orderly galaxies, allowing them to explore how they are. form and evolve in the early universe.


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