Radio waves detected explosions from dwarf galaxies billions of light-years away

Astronomers have detected a mysterious fast and repeating radio burst emanating from a dwarf galaxy 3 billion light years away.

The cosmic object is distinctive from other detections radio bursts in recent years, according to new research.

Watch the video above to see the first time a fast radio blast has been traced back to its source

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Fast Radio Bursts, or FRBs, are millisecond-long bursts of radio waves in space.

Individual radio bursts transmit once and do not repeat. But repeating fast radio bursts are known to send short, energetic radio waves multiple times.

Astronomers have been able to trace some radio bursts back to their home galaxies, but have yet to determine the actual cause of the pulses.

Knowing more about the origin of these bright and intense radio emissions could help scientists understand what causes them.

Astronomers detected the object, named FRB 190520, when it emitted a burst of radio waves on May 20, 2019.

Researchers used the Five Hundred Meter Aperture Spherical Radio Telescope (FAST) in China and discovered the burst data from the telescope in November 2019.

When making follow-up observations, the astronomers noticed something unusual – the object was emitting frequent and repeated bursts of radio waves.

Artist’s impression of a neutron star with an ultra-strong magnetic field, called a magnetar, emitting radio waves (in red). Credit: Bill Saxton/NRAO/AU/NSF

The team used the Karl G. Jansky Very Large Array (VLA) of National Science Foundation Telescopes in 2020 to identify the origin of the burst before focusing on it using the Subaru Telescope in Hawaii.

Subaru’s visible-light observations showed that the burst originated from the outskirts of a distant dwarf galaxy.

A study detailing the results has been published in the log Nature Wednesday.

two of a kind

VLA observations also revealed that the celestial object was constantly releasing weaker radio waves between repeated bursts.

It’s very similar to only one other known repeating fast radio burst: FRB 121102, discovered in 2016.

The initial detection and subsequent tracing of FRB 121102 returning to its point of origin in a small dwarf galaxy more than 3 billion light-years away was a breakthrough in astronomy.

It was the first time astronomers could learn more about the distance and surroundings of these mysterious objects.

This image, captured by the Karl G. Jansky Very Large Array, shows object FRB 190520 when active (in red). Credit: NRAO, Bill Saxton/NSF, AUI, CFHT

“Now we actually need to explain this double mystery and why FRBs and persistent radio sources sometimes end up together,” said study co-author Casey Law, a California Institute of Technology scientist in radio astronomy.

“Is this common when FRBs are young? Or maybe the bursting object is a massive black hole disorderly devouring a nearby star?

“Theorists have a lot more detail to work with now, and the scope of the explanation is narrowing.”

Currently, less than 5% of the hundreds of identified fast radio bursts repeat themselves and only a few of them are regularly active.

But FRB 190520 is the only persistently active one, meaning it has never “gone out” since its discovery, said Di Li, study author and chief scientist of the Observatories’ radio division. National Astronomical Institutes of China and the FAST Operations Center.

Meanwhile, FRB 121102, “the first known famous repeater, may die out for months,” Li said.

New questions for FRBs

The latest findings raise more questions as astronomers now wonder if there could be two types of fast radio bursts.

“Are those who rehearse different from those who don’t? What about persistent radio emission – is it common? a study co-author involved in the study as a doctoral student at West Virginia University, Kshitij Aggarwal, said in a statement.

It is possible that there are different mechanisms that cause radio bursts, or that what produces them behaves differently during different evolutionary stages.

Previously, scientists had speculated that fast radio bursts were caused by the dense remnants left behind after a supernova, called a neutron star, or neutron stars with incredibly strong magnetic fields called magnetars.

FRB 190520 was considered a possible “newborn” object because it was located in a dense environment, Law said.

This environment may be caused by materials released by a supernova, which resulted in the creation of a neutron star.

As this material disperses over time, the splinters of FRB 190520 may decrease as it ages.

In the future, Li wants to experience faster radio bursts.

“A consistent picture of the origin and evolution of FRBs is likely to emerge in just a few years,” Li said.

Law is excited about the implications of having a new class of radio wave sources.

“For decades, astronomers thought there were basically two types of radio sources we could see in other galaxies: accretion of supermassive black holes and star-forming activity,” he said. Law.

“Now we say it can no longer be an either/or categorization!”

“There is a newcomer in town and we should take this into account when studying radio source populations in the universe.”

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