Radio telescope reveals thousands of star-forming galaxies in the early universe

The images capture drama billions of years ago in the early Universe – glittering galaxies, glowing from stars exploding in supernovae and burning jets shot out of black holes.

Europe’s giant LOFAR radio telescope has discovered stars born in tens of thousands of galaxies with unprecedented precision, in a series of studies published on Wednesday.

Using techniques that correspond to a very long exposure and with a field of view about 300 times the size of the full moon, scientists were able to make out galaxies such as the Milky Way deep in the ancient universe.

“The light of these galaxies traveled billions of years to reach the earth; that means we see the galaxies as they were billions of years ago, when they formed most of their stars,” said Philip Best of Britain. University of Edinburgh, which in a press release led the in-depth survey of the telescope.

The LOFAR telescope combines signals from a large network of more than 70,000 individual antennas in countries from Ireland to Poland, connected by a high-speed optical fiber network.

They are able to perceive very faint and low-energy light, invisible to the human eye, created by ultra-energetic particles moving near the speed of light.

According to researchers, they can study supernova star explosions, collisions of galaxies and active black holes that accelerate these particles into shocks or rays.

By observing the same parts of the sky and compiling the data to create a single very long exposure image, the scientists were able to detect the radio glow of exploding stars.

The farthest objects observed were from when the universe was only a billion years old. It is now about 13.8 billion years old.

“When an galaxy forms stars, many stars explode at the same time, accelerating many energy particles, and galaxies begin to radiate,” said Cyril Tasse, an astronomer at the Paris Observatory and one of the authors of the research. published in a series of articles in the magazine Astronomy & Astrophysics.

About 3 billion years after the big bang, he said “these are really fireworks” in the young galaxies, with a “peak of star formation and black hole activity”.

The telescope focused on a wide portion of the Northern Hemisphere’s sky, with an equivalent of an exposure time ten times longer than the use of the first cosmic map in 2019.

“It gives much finer results, like a photo taken in the dark, the longer your exposure, the more things you can distinguish,” Tasse told AFP.

The deep images are produced by combining signals from the telescope’s thousands of antennas, which contain more than four petroglyphs of raw data – equivalent to about one million DVDs.

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© 2021 AFP