A strongway in the newborn universe actually looks like a full grown adult if it is to look just like a small child. New findings suggest that galaxies can evolve much faster than previously thought.
Galaxies come in different shapes, colors and sizes. Many remain a mystery about how galaxies formed in the early universe and how they developed mature features, such as rotating disks and central bumps of densely packed stars. To look so far back in time, astronomers have to look at the stars of distant galaxies, but such targets are often too dim to see well.
In the new study, researchers focused on the galaxy ALESS 073.1,. The starlight they detected from this galaxy comes from 12.5 billion years ago, when ‘the universe was 1.2 billion years old, about 10% of its current age’, lead author Federico Lelli, an astrophysicist, told Cardiff University in Wales, told Space. com
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Using the Atacama Large Millimeter / Submillimeter Array (ALMA) in Chile, the scientists analyzed high-quality images they had successfully collected from ALESS 073.1’s dust and gas. They used this data to concentrate matter in the galaxy and calculate its motions.
Unexpectedly, the researchers discovered that the galaxy possesses a rotating disk and a central hump. They also found signs that it could even have the same kind of spiral arms as adult galaxies like the Milky Way extending from their core.
“This galaxy looks like a full-grown adult, but it should only be a small child,” Lelli said.
ALESS 073.1’s core also produced more energy than could be explained by stars. Previous work has suggested that such an ‘active galactic nucleus’ (AGN) indicates the presence of a supermassive black hole that is millions to billions of times the solar mass.
Previously, researchers thought that central bumps formed slowly over time due to gravitational instability in a galaxy, or fusion between galaxies. “ALESS 073.1 could form instead of a large mound, making up about half of its stars in less than 1.2 billion years,” Lelli said. “This young galaxy looks surprisingly mature.”
Previous research has also suggested that galaxies forming in the primeval universe are generally expected to be chaotic, turbulent, and largely unstructured because of all the activities they go through, such as devouring gas from their environment and stars against to form very high prices. “The orderly structure found within ALESS 073.1 is contrary to these expectations,” said Lelli.
These new findings suggest that galaxies may be much faster and more efficient than previously thought, mature traits such as disks and bumps. “Structures such as bulges, regular rotating disks and possibly spiral arms must form within less than a billion years, which is a high order for current models of galaxy formation,” Lelli said.
In the future, scientists plan to collect similar high-quality images for a dozen galaxies from the same cosmic era, Lelli said.
“These new observations will determine whether galaxies like ALESS 073.1 are the rule or the exception in the primeval universe,” Lelli said. “The observations would have taken place last year, but unfortunately the ALMA Observatory was closed due to the COVID-19 emergency.”
The scientists presented their findings in the journal Science on 12 February.
Originally published on Space.com.