Astronomers have just found two previously unseen galaxies. Their discovery has led scientists to doubt our perspectives about the universe's evolution since the "Big Bang" brought our universe into existence.
"REBELS-12-2" and "REBELS-29-2" are the names of the two new galaxies. Because these objects originated shortly after the Big Bang, the light from these galaxies took 13 billion years to reach us. These ancient galaxies are around 29 billion light-years away from Earth due to the universe's continuous expansion.
The "rebellious" galaxies, according to the researchers, are hidden by a thick coating of cosmic dust. This rendered them invisible to the Hubble Space Telescope's optical lens, which was deployed in 1990 and is one of the world's largest and most flexible telescopes, regarded as a key scientific instrument as well as a public relations boon for astronomy.
Researchers detailed their study, titled "Normal, Dust-Obscured Galaxies in the Epoch of Reionization," in the journal Nature.
'Invisible' Galaxies Exposes Our Cloudy View of the Cosmos
Pascal Oesch, an astronomer from the Cosmic Dawn Center at the Niels Bohr Institute in Copenhagen, explained in a statement that the team examined a sample of highly distant galaxies that they already knew existed thanks to the Hubble Space Telescope.
According to Oesch, some of their light is obstructed as both of these nearby galaxies are shrouded by dust. Hence, the galaxies looked invisible to Hubble. Then the team saw that two galaxies had a companion that researchers did not anticipate to be there at all.
According to Gizmodo, Oesch is a specialist at locating the universe's most distant galaxies. He and his colleagues discovered the 13.4 billion-year-old GN-z11 galaxy in 2016, breaking the cosmic distance record. Only 400 million years after the Big Bang, GN-z11 was born.
The new research explains how ALMA and a novel observational approach developed by Oesch and colleagues might help find similarly shrouded ancient galaxies. And it appears that there are many more waiting to be discovered. According to Oesch, the scientists matched the two newly discovered galaxies to previously known galactic origins in the early cosmos, which led them to believe that "up to one in five of the oldest galaxies may have been absent from our picture of the skies."
In fact, the new article claims that there were more ancient galaxies in the early cosmos than previously thought. This is crucial because the first galaxies served as the foundation for later galaxies. As a result, astronomers may be working with a defective or otherwise wrong picture of the early cosmos until we obtain a "proper accounting," as Oesch phrased it.
The problem now will be to locate these missing galaxies, and happily, a forthcoming instrument, the Webb Space Telescope, promises to make this work much simpler. "This next-generation telescope will be far more sensitive than Hubble and capable of investigating longer wavelengths," Oesch added, "which should allow us to discover these hidden galaxies with ease."
The new article may thus be tested since Webb's findings are likely to confirm, refute, or revise the researchers' predictions. The space telescope is set to launch from French Guiana at 7:20 a.m. ET on Wednesday, December 22.
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