https://esahubble.org/news/heic2402/

Astronomers using the Hubble Space Telescope have discovered a rare, strange event in a strange place.

Fast radio bursts (FRBs) are brief but incredibly bright cosmic events. One recently discovered FRB, FRB 20220610A, stands out due to its distance and energy. It is located in a galaxy cluster dating back to when the universe was only 5 billion years old. This event challenges existing models of FRBs because its origin, pinpointed using the advanced imaging of the Hubble telescope, suggests complex interactions between up to seven merging galaxies.

A fast radio burst (FRB) is a fleeting burst of energy that can outshine an entire galaxy for a few milliseconds. Hundreds of FRBs have been discovered in recent years. They shoot across the sky like camera flashes at a stadium event, but the sources of these intense bursts of radiation remain unclear.

This FRB is particularly strange because it erupted on the other side of the universe, making it the most distant and strongest radiation burst ever recorded.

And if that wasn’t strange enough, Hubble’s follow-up observations after its discovery made it even stranger. The FRB flashed up in a seemingly unlikely place, a cluster of galaxies that existed when the universe was only 5 billion years old. Previous FRBs have been found in isolated galaxies.

FRB 20220610A was first discovered on June 10, 2022 by the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope in Western Australia and confirmed to have originated from a distant region by the European Southern Observatory radio telescope. Very large telescope in Chile. It is four times more energetic than closer FRBs. This could challenge models of what creates FRBs. Or could it be a selection effect where only very bright FRBs on the other side of the Universe can be detected?

“To pinpoint the origin of the FRB, Hubble’s enormous sharpness and sensitivity were required,” said lead author Alexa Gordon of Northwestern University in Evanston, Illinois. “Without the Hubble images, it would still be a mystery whether this is from a monolithic galaxy or some kind of interacting system. It’s these kinds of environments – these strange ones – that lead us to better understand the mystery of FRBs.”

Hubble’s sharp images suggest that as many as seven galaxies could be on their way to merging, which would also be very significant, researchers say. Such groups of galaxies are rare, and it’s possible that this led to the conditions that triggered the FRB.

“Ultimately, we are trying to answer the questions: What causes them? What are their precursors and what are their origins? The Hubble observations provide a spectacular look at the surprising types of environments that give rise to these mysterious events,” said co-investigator Wen-fai Fong, also of Northwestern University.

Although astronomers do not agree on the possible mechanism of this extraordinary phenomenon, it is generally believed that FRBs must contain some kind of compact object, such as a black hole or Neutron star. An extreme type of neutron star is called a magnetar – the type of neutron star with the strongest magnetic force in the universe. It has a magnetic field so strong that a magnetar located halfway between the Earth and the Moon would erase the magnetic strip on every credit card in the world. Worse still, if an astronaut were to get within a few hundred kilometers of a magnetar, he would practically dissolve it, because every atom in her body would be disturbed.

Possible mechanisms include some kind of violent starburst, or alternatively an explosion created when the twisted magnetic field lines of a magnetar rupture and reconnect. A similar phenomenon occurs on the Sun, causing solar flares, but a magnetar’s field is a trillion times stronger than the Sun’s magnetosphere. The rupture would create an FRB flash, or a shock wave that burns up surrounding dust and heats gas into a heat wave. plasma.

There could be several types of magnetars. One could be an exploding object orbiting a black hole surrounded by a disk of matter. Another possibility is a pair of neutron stars orbiting each other, their magnetospheres interacting periodically to form a cavity in which outbursts can occur. Magnetars are estimated to be active for about 10,000 years before settling down, so you would expect to find them where there is a firestorm of star formation. But that doesn’t seem to be the case for all magnetars.

In the near future, FRB experiments will increase their sensitivity, resulting in an unprecedented number of FRBs being discovered at these distances. Hubble will play a crucial role in characterizing the environments in which these FRBs occur. Astronomers will soon learn just how special the environment of this FRB was.

“We just need to continue to find more of these FRBs, both near and far and in all these different types of environments,” Gordon said.

The results were presented at the 243rd meeting of the American Astronomical Society in New Orleans, Louisiana.