Science

Over 1000 space explosions detected in 47 days

FAST catches the actual pulse from FRB121102. Credit: NAOC

An international research team led by Professor LiDi of the National Astronomical Observatory of China (NAOC) and Dr. Wang Pei used 500 meters to capture an extreme episode of a space explosion from a fast radio burst (FRB) 121102. Aperture Spherical Radio Telescope (FAST). A total of 1,652 independent bursts were detected within 47 days of August 29, 2019 (UT).


This is the largest set of Fed events to date, more than the combined number reported in all other publications. Such a burst set allows the Fed’s characteristic energy and energy distribution to be determined for the first time, allowing it to shed light on the central engine that powers the Fed.

These results were published in Nature October 13, 2021.

The Fed was first detected in 2007. These space explosions can occur in as little as a thousandth of a second, producing a year’s worth of the total energy output of the Sun. The origin of the Fed is still unknown. Even aliens have been considered in the Fed’s model, but natural causes are clearly supported by observations.Recent focus includes exotic supermagnetization Neutron star, Black Hole, And the cosmic string left from the Big Bang.

Scientists have found that a small portion of the Fed repeats itself. This phenomenon facilitates follow-up, including locating and identifying the Fed’s host galaxy.

The Fed 121102 was the first known repeater and the first fully localized Fed. Scientists have confirmed that the dwarf galaxy has its origins. In addition, this Fed is clearly associated with a permanent source of radio waves. Both clues are important for solving the Fed’s cosmic mystery. The behavior of FRB 121102 is difficult to predict and is commonly described as “seasonal”.

Over 1000 space explosions detected by FAST in 47 days

Burst straight distribution of isotropic equivalent energy at 1.25 GHz for FRB121102. Credit: NAOC

While testing the FAST FRB backend during the commissioning phase, the team noticed that the FRB 121102 was frequently operating with bright pulses. Between August 29 and October 29, 2019, 1,652 independent burst events were detected in a total of 59.5 hours. Burst cadence changed during the series, but 122 bursts were seen during peak hours. This corresponds to the highest event rate ever observed in the Fed.

Such high cadence facilitates statistical studies of these Fed bursts.Researchers have discovered a distinctive characteristic energy of E0= 4.8 × 1037 If it is less than erg, the burst generation efficiency will decrease. The burst energy distribution can be well described as bimodal, that is, the low E-burst lognormal function and the high E-burst Lorentz function. This means that weak Fed pulses are stochastic in nature and strong ones have two ratios. Independent amount.

Over 1000 space explosions detected by FAST in 47 days

A burst “river” from a galaxy recorded by the FAST telescope. Burst counts and energies are displayed in a histogram, mimicking the Song dynasty’s royal west gate painting, “The Vast Land.” Credit: NAOC

“The total energy of this burst set reached 3.8% of the energy obtained from the magnetar, with no periodicity between 1 ms and 1000 seconds, both of which are derived from the FRB 121102 isolated compact object. It severely limits the possibilities, “Dr. Wang said.

More than six new Feds have been discovered through the Commensal Radio Astronomy FAST Survey, including one new 121102-like repeater. “The sensitivity of FAST, the world’s largest antenna, has proven to help uncover the complexity of transients in the universe, including the Fed,” said Professor LI.

This project has been part of a long-standing collaboration since the commissioning phase of the FAST telescope. Major partner institutions include Guizhou Normal University, University of Nevada Las Vegas, Cornell University, Max-Planck-Institut fuer Radioastronomie, West Virginia University, CSIRO, University of California Berkeley and Nanjing University.


FAST helps clarify the origin of fast radio bursts


For more information:
Di Li, Bimodal Burst Energy Distribution of Repeated Fast Radio Burst Sources, Nature (2021). DOI: 10.1038 / s41586-021-03878-5.. www.nature.com/articles/s41586-021-03878-5

Quote: More than 1,000 space explosions detected in 47 days (October 13, 2021) from https: //phys.org/news/2021-10-thousand-cosmic-explosions-days.html in October 2021 Obtained on the 14th.

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