Two new ancient galaxies have been discovered


Artist's impression of an ancient galaxy.

Artist’s impression of an ancient galaxy.
picture: University of Copenhagen / NASA

The presence of two previously undiscovered galaxies about 29 billion light-years away suggests that our understanding of the early universe suffers from a disturbing lack of it.

Introducing REBELS-12-2 and REBELS-29-2 – two galaxies we didn’t know existed until recently. It took the light from these galaxies 13 billion years to reach here, as these objects formed shortly after the Big Bang. The ongoing expansion of the universe places these ancient galaxies about 29 billion light-years from Earth.

new Research The publication in Nature notes that REBELS-12-2 and REBELS-29-2 have escaped detection up to this point because our view of these galaxies is obscured by thick layers. from cosmic dust. The Hubble Space Telescope, despite its power, could not look through the celestial fog. It took very sensitive ALMA radio telescope in Chile to discover galaxies, in what turns out to be an accident.

“We were looking at a sample of very distant galaxies, which we already knew existed from the Hubble Space Telescope. Then we noticed that two of them had a neighbor we didn’t expect to be there at all,” explained Pascal Auch, an astronomer from the Cosmic Dawn Center at the Institute Niels Bohr in Copenhagen, in statment. “Because both neighboring galaxies are surrounded by dust, some of their light is obscured, making them invisible to the Hubble telescope.”

Osh is an expert in finding some of the most distant galaxies in the universe. Back in 2016, he and his colleagues discovered the 13.4 billion-year-old galaxy GN-z11, giving rise to a Cosmic distance record. GN-z11 formed only 400 million years after the Big Bang.

The ALMA telescope made this discovery possible.

The ALMA telescope made this discovery possible.
picture: University of Copenhagen / NASA

The new paper describes how ALMA and a new observational technique developed by Oesch and colleagues can detect similarly obscured ancient galaxies. There seems to be a lot Waiting for discovery. Astronomers have compared the two newly discovered galaxies to previously known galactic sources in the early universe, leading them to suspect that “up to one in five of the oldest galaxies may be missing from our map of the sky,” Ochs said.

He added to him: “Before we begin to understand when and how galaxies formed in the universe, we first need a proper computation.” In fact, the new paper confirms that there were more ancient galaxies in the early universe than previously thought. This is important because the first galaxies formed the building blocks of later galaxies. So, until we get a “proper calculation,” as Ochs puts it, astronomers can work with an imperfect or otherwise inaccurate model of the early universe.

The task now will be to find these lost galaxies, and thankfully there is an upcoming instrument that will make this task considerably easier: the Webb Space Telescope. This next-generation observatory, Ochs said, “will be more sensitive than Hubble and able to investigate at longer wavelengths, allowing us to easily see these hidden galaxies.”

Thus, the new paper is testable, as Webb’s observations are likely to confirm, deny or further refine the predictions made by the researchers. Due to the space telescope launch From French Guiana on Wednesday, December 22 at 7:20 a.m. ET (4:30 a.m. PT).

more: NASA says the Webb Telescope was undamaged after a surge accident.



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