Giant galaxies discovered from the early days of the universe

Astronomers using the James Webb Space Telescope have apparently discovered six giant galaxies from the early days of the Universe. They were formed about 600 million years after the Big Bang and are much larger than expected, wrote Ivo Labbé from Swinburne University in Melbourne and his colleagues in an article published in the journal Nature. Each of the six objects is billions of times larger than our sun.

The James Webb telescope has already detected older galaxies - some were formed as early as 300 million years after the Big Bang. But the size and maturity of the galaxies now discovered is amazing, the scientists wrote.

Labbé admitted that at first he and his colleagues couldn't believe the results. The objects are so big and so bright that some team members thought they had made a mistake. "We were overwhelmed, kind of stunned," he wrote. The discovery must also be checked and confirmed.

Labbé explained that most galaxies from this period are small and growing slowly. He therefore expected baby galaxies, but not such giant structures. “There are a few monsters that fast-track to maturity. Why this is the case or how it works is unknown,” writes Labbé.

His collaborator Joel Leja of Pennsylvania State University said the discovery turned some accepted scientific knowledge on its head. "It turns out that we've found something so unexpected that it's becoming a problem for science. This challenges the whole picture of how early galaxies formed,” he explained.

Leja explained the researchers are awaiting confirmation from sensitive spectroscopy and are cautious about labeling these candidates as massive galaxies. Some candidates may not be galaxies but supermassive black holes. Others may be smaller than currently thought.

Labbé said the chances that at least some of them are actually giant galaxies are good. "Next year will tell." But it's clear: anyone who works with James Webb has to say goodbye to their expectations and be prepared for surprises.

The James Webb telescope, built by the USA, Canada and the European space agency ESA, was launched from French Guiana at the end of 2021 and has been peering into the depths of space 1.6 million kilometers from Earth since last summer.

Scientists hope to use the device, which costs ten billion dollars, to look back to the formation of the first stars and galaxies 13.7 billion years ago and gain new insights into the formation of the universe.