The existence of two previously unknown galaxies, some 29 billion years after the light of the earth, indicates that our understanding of the early universe is sadly lacking.
Introducing REBELS-12-2 and REBELS-29-2 – two galaxies that, until recently, we did not even know. The light emanating from these galaxies took 13 billion years to reach, since the material was formed shortly after the Big Bang eruption. The continuous expansion of the universe puts these ancient galaxies into the nearly 29 billion light years from Earth.
New research published in Nature shows that REBELS-12-2 and REBELS-29-2 are still unknown because of the glare of our galaxies. of cosmic dust. The Hubble Space Telescope, though as powerful as it is, could not look into the fog of space. It took ultra-sensitive ALMA radio telescope in Chile to see the galaxies, in an accident that occurred accidentally.
“We were looking at an example of the farthest galaxy, which we already knew existed from the Hubble Space Telescope. Then we discovered that the two of them had a neighbor we did not expect to find,” said Pascal Oesch, a scientist at the Cosmic Dawn Center at Niels Bohr Institute. in Copenhagen. words. “When all the surrounding galaxies are surrounded by dust, some of their light is blocked, making it invisible to Hubble.”
Oesch is an astronomer and explorer. Back in 2016, he and his colleagues discovered the 13.4 billion-year-old GN-z11 galaxy, establishing cosmic distance history. GN-z11 only made 400 million years after the Big Bang.
The new paper describes how ALMA and the new observing technique developed by Oesch and his colleagues might be able to spot similarly obscured ancient galaxies. And there’s apparently many more awaiting discovery. The astronomers compared the two newly detected galaxies to previously known galactic sources in the early universe, leading them to suspect that “up to one in five of the earliest galaxies may have been missing from our map of the heavens,” Oesch said.
To which he added: “Before we can start to understand when and how galaxies formed in the Universe, we first need a proper accounting.” Indeed, the new paper asserts that more ancient galaxies existed in the early universe than previously believed. This is significant because the earliest galaxies formed the building blocks of subsequent galaxies. So until we have a “proper accounting,” as Oesch put it, astronomers could be working with a deficient or otherwise inaccurate model of the early universe.
The task now will be to find these missing galaxies, and thankfully an upcoming instrument promises to make this job considerably easier: the Webb Space Telescope. This next-gen observatory, said Oesch, “will be much more sensitive than Hubble and able to investigate longer wavelengths, which ought to allow us to see these hidden galaxies with ease.”
The new paper is thus testable, as observations made by Webb are likely to confirm, negate, or further refine the predictions made by the researchers. The space telescope is scheduled to startup from French Guiana Wednesday December 22 7:20 am ET (4:30 am PT).