A peculiar form of quick radio burst was found three billion light-years away in space

This may indicate more than one explanation for quick radio bursts.

 

Astronomers using two of the world's largest radio telescopes found the second known instance of a new form of fast radio burst (FRB). FRBs are unexplained, extraordinarily explosions of radio waves that occur thousands of times per day in space.

 

The newly discovered FRB, which goes by FRB 190520, provides compelling evidence that these mysterious signals could be coming from a combination of different heavenly bodies.

 

The new object is the second one that produces recurrent FRBs and releases a constant source of radiation that is less powerful in between eruptions. This new object was discovered. A study published on June 8 in Nature provided a comprehensive explanation of the signal.

 

Fast radio bursts were discovered for the first time in 2007, and they release more energy in a few milliseconds than the sun does in an entire year. Since the beginning of time, astronomers have been perplexed by what causes these short, bright flashes. It is exceedingly difficult to determine where supernovae originate because they often originate from galaxies that are located millions or even billions of light-years away. They explode very quickly, and most of the time, they do so only once.

 

In 2020, scientists made the historic discovery of the first-ever FRB within our galaxy. This discovery allowed them to determine that the FRB originated from a magnetar, the highly magnetic and rapidly rotating remnant of a dead star. Magnetars are a subcategory of neutron stars, which are very dense stellar corpses that are left behind after supernova explosions. Magnetars are the only known examples of their kind. Magnetars possess extraordinarily powerful magnetic fields, trillions of times more powerful than Earth's. However, scientists aren't entirely convinced that FRBs always originate from magnetars.

 

Even more peculiar is that the flashes emitted by some FRBs recur, sometimes in the form of a single quick burst and other times as many random repetitions. FRB 121102 is the first of these repeated FRBs and also the one that has the highest activity. The unidentified source, located in a dwarf galaxy three billion light-years away, emits radio waves from a concentrated area over 157 days. It alternates between 90 days of powerful, repetitive radio bursts and 67 days of softer, weaker radio emissions. FRB 121102 is extremely active, as evidenced by the fact that it has been recorded spitting out 1,652 flares over 47 days. For a long time, astronomers believed it was the only one of its sort. However, they have since discovered that there is another.

 

Using China's five-hundred-meter Aperture Spherical radio Telescope, the researchers could catch their initial glimpses of the newly discovered rapid radio burst designated FRB 190520 (FAST). Later observations with New Mexico's Very Large Array (VLA) located its location, confirming that the distant object was generating frequent and repetitive radio bursts. FAST was the instrument that made the initial discovery. The source of the frequent bursts, which scientists discovered, was located in a dwarf galaxy approximately three billion light-years away from Earth, similar to the source of its cousin.

 

The VLA was also able to determine that the source of FRB 190520 was a small and compact object and that it was leaking weaker radio emissions in the gaps between its more powerful flashes.

 

According to the researchers, the discovery of a second FRB that exhibits behaviour comparable to that of the first FRB raises several significant problems and lends credence to the idea that there may be two distinct varieties of FRB.

 

Is there a difference between people who repeat themselves and those who don't? What about the constant radio emission; is that something that happens all the time? Kshitij Aggarwal, an astronomer and doctoral student at West Virginia University who contributed to the study and was also one of its authors, said in a release that.

 

Astronomers think these astounding cosmic flashes are caused by two or more entirely separate mechanisms existing in the universe or by things in very different phases of their cosmic evolution.

 

A few pieces of circumstantial evidence support the second theory. Astronomers typically estimate how far away the source is from Earth by measuring how much an FRB's emitted radio waves are separated by frequency (like a light after it has passed through a prism). This happens to them the more often they encounter free electrons in space. Since FRBs typically arrive as single pulses from an unknown origin, this is how astronomers measure how far away the source is from Earth. This effect, referred to as dispersion, gives astronomers a good approximation of how far a radio flash has travelled before it reaches telescopes on Earth. This approximation is based on the assumption that electrons are rather evenly scattered across space.

 

But the fact that we could track down the origin of FRB 190520's signal sheds light on a peculiar discrepancy. The radio waves from the pulsing object were scattered enough that they could have originated from something between 8 billion and 9.5 billion light-years away. However, by analyzing the Doppler shift, which is the stretching out of the wavelengths of the radio waves caused by the universe's expansion, the astronomers were able to more accurately place the object at a distance of slightly less than 3 billion light-years from Earth.

 

According to Aggarwal, "this indicates that there is a significant amount of material near the FRB that would confuse any attempt to use it to estimate the gas that exists between galaxies." If this is the case with other people, we cannot rely on FRBs to serve as cosmic yardsticks.

 

The source of the FRB may be a "newborn" magnetar that is still cloaked in the material of the supernova explosion that generated it, as suggested by the extremely dense electron clouds that surround it. However, the researchers will need to take many more measurements before they can be certain.

 

"The field of FRB is currently moving at a very rapid pace, and new discoveries are being made on a monthly basis." Nevertheless, there are still a lot of important concerns, and this object is providing us with perplexing clues about those problems. Sarah Burke-Spolaor, an assistant professor of astronomy at West Virginia University and a co-author of the study, commented on the findings in the statement.

Article source : https://www.livescience.com/second-repeating-fast-radio-burst-found

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