Astronomers have discovered essentially the most distant example of a galaxy within the universe that appears like our home galaxy, the Milky Way.
When the universe was just two billion years old, the newfound spiral galaxy, ceers-2112, appears to have featured a bar of stars and gas cutting across its heart, like a slash across a no-smoking sign. The Milky Way, also a spiral galaxy, sports a similar bar. Scientists suspect the Milky Way’s bar rotates cylindrically, like a toilet roll holder does as you unravel toilet paper, funneling gas into the galaxy’s center and sparking bursts of star formation.
Astronomers previously thought this galactic structure marks the tip of a galaxy’s childhood, so it was expected to be seen only in old galaxies which will have reached full maturity — perhaps those who existed halfway through the evolution of the universe. Indeed, the Hubble Space Telescope‘s past observations of galaxy morphologies have shown the early universe hosted only a few barred galaxies.
Nevertheless, the brand new findings, gleaned from data by the James Webb Space Telescope (JWST), conclude it is probably not necessarily true that barred spirals must’ve roamed the universe for therefore long. The invention of spiral galaxy ceers-2112 reveals galaxies that resemble our own already existed 11.7 billion years ago, “when the universe had just 15 percent of its life,” Luca Costantin, an astrophysicist on the Centro de Astrobiología in Madrid and the lead creator of the brand new study, told Space.com.
The JWST can collect six times more light than Hubble, allowing for more detailed features of faraway galaxies to come into sight. Ceers-2112 is observed at a redshift of three, when the universe was 2,100 million years old. Essentially, this implies the sunshine from the galaxy took 11.7 billion years to achieve the JWST, Costantin said. This can be a surprising find, because the galactic bars are seen in roughly two-thirds of all spiral galaxies, but bars are thought to have manifested about 4 billion years into the birth of the universe.
Studying detailed morphologies of faraway galaxies “is important to grasp their history, opening the door to latest scenarios about galaxy formation and evolution,” study co-author Cristina Cabello, who’s a researcher on the Instituto de Física de Partículas y del Cosmos in Madrid, said in a press release.
The presence of the bar in ceers-2112, as an illustration, challenges current theoretical models that predict the early universe’s physical conditions should have prevented the formation of barred galaxies generally, Costantin said.
“Theoretical predictions from cosmological simulations really struggle to breed such systems at those epochs,” he told Space.com. “We now need to grasp which key physical ingredient is missing in our models — if something is missing.”
Further, studies like these are also shaping our understanding of the role dark matter played within the early universe.
Astronomers think 85 percent of all matter within the universe is dark matter, a mysterious substance elusive to telescopic observations since it doesn’t interact with light in any respect. Dark matter is believed to have radically influenced galaxy evolution and star formation from as early as 380,000 years after the Big Bang. Findings from the brand new study, nevertheless, show galaxy evolution, at the least within the case of ceers-2112, was dominated by unusual matter and never dark matter when the universe was about two billion years old. The galaxy’s morphology shows that the contribution of dark matter within the galactic bar of ceers-2112 could be very low and is as an alternative dominated by normal matter, the study finds.
“This discovery confirms that the evolution of this galaxy was dominated by baryons — the unusual matter we’re manufactured from — and never by dark matter, despite its over-abundance, when the universe had only 15 percent of its actual age,” said study co-author Jairo Abreu, who’s a researcher at University of La Laguna.
“JWST, in only one yr of observations, is revolutionizing our understanding of the early universe,” said Costantin. “In the following 5-10 years, I personally plan to proceed exploiting its extraordinary capabilities, investigating the detailed structure of the primary galaxies assembled within the universe.”
This research is described in a paper published Wednesday (Nov. 8) within the journal Nature.