It has gone through a lot of hardships and traveled 8 billion light years to see you

Fast radio bursts (FRBs) are mysterious radio astronomical phenomena from outside the Milky Way. They burst in a short time but are extremely bright.

A study published in Science on October 19 reported the farthest-traveling fast radio burst ever discovered by scientists. Before being detected by telescopes on Earth, its bright, short, detectable flashes had spread rapidly across the universe for about 8 billion light-years . Its energy was more than three times that expected, challenging the current model of fast radio bursts.

A fast radio burst from a galaxy 8 billion light-years from Earth. Image credit: ESO/M. Kornmesser

The age of this fast radio burst surprised scientists. "We didn't even know there were fast radio bursts at that time," said Stuart Ryder, an astronomer at Macquarie University in Australia and a co-author of the study.

This unusual fast radio burst, FRB 20220610A, was detected by Ryder and his colleagues using the Square Kilometer Array telescope in Western Australia in June 2022. In addition, they used the European Southern Observatory's Very Large Telescope in Chile and the Keck Observatory in Hawaii, USA, to pinpoint the galaxy of origin of FRB 20220610A.

Image credit: ESO/M. Kornmesser

Ryder pointed out that this means that radio waves of different frequencies are observed at different times by telescopes on Earth, allowing scientists to infer whether there is hot matter causing dispersion. This is something that other types of telescopes cannot observe. Therefore, fast radio bursts are a powerful tool for analyzing the universe, allowing scientists to detect and measure intergalactic matter that is currently difficult for humans to see.

The signal of FRB 20220610A is more scattered than most fast radio bursts observed before, and it has obviously experienced many "ups and downs" in its long journey of 8 billion light years. The unusually scattered signal and the long distance of the galaxy where the radio burst originated confirm the scientists' previous research results, that is, the farther the origin of the fast radio burst is from the earth, the more scattered their signals are when they reach the latter.

In addition, the energy emitted by FRB 20220610A is also very strong, 3.5 times the maximum energy predicted by modeling. "This helps us refine our estimates of the energy distribution of fast radio bursts," said Ryder.

So, what caused this outbreak?

By observing the origin galaxy of FRB 20220610A, the researchers found that the galaxy is composed of two or three bright clumps. This suggests that fast radio bursts may come from the collision of a group of galaxies, which is very common in the early universe. "Many galaxies gathered and a major 'galaxy traffic accident' occurred." Ryder said. Next, Ryder's team plans to explore fast radio bursts to better understand the conditions in the early universe that produced powerful explosions and provide more clues for the study of cosmic evolution.

Planning and production

Source: China Science Daily (ID: china_sci)

Author: Xu Rui

Editor: Bai Li