Brief Introduction of Fast Radio Burst The short and bright radio burst that suddenly appeared in the distant universe has been puzzling astronomers since it was first reported nearly ten years ago. Only a few of these mysterious events have been confirmed, but previous observations have not revealed how or even where they happened.
After analyzing nearly 700 hours of data archived by the National Science Foundation (NSF) Green Dam Telescope (GBT), a group of astronomers discovered a fast radio burst event with the most details so far. These newly analyzed data, including linear polarization data and circular polarization data, indicate that the explosion occurred in a highly magnetized area, which may be a recent supernova or an active star-forming nebula.
A fast radio burst is a brief flash of unknown origin detected by a radio telescope. Although it lasts less than a second, it contains more energy than our sun has given off for hundreds of thousands of years. So far, only the 1 1 FRB event has been confirmed, but astronomers believe that thousands of such explosions occur every day in the observable universe. However, in order to find them, it is necessary to carefully analyze the current and archived daily radio astronomical observation records.
In the fast radio burst observed before, only circularly polarized data were detected. Part of the reason for this situation is the observation ability of the telescope and the limitation of the data that the telescope can store. Green dike telescope not only has the ability to detect complete polarized images, but also has enough observation data for archiving.
By studying the newly detected linear polarization data, the researchers found that the radio waves emitted by the rapid radio burst show Faraday rotation effect, which is a spiral twist that appears when the radio waves pass through a strong magnetic field, and its shape is like a screwdriver that opens a cork of a wine bottle.
Further analysis of the signal shows that it passed through two different ionized gas regions on the way to the earth, which are called (scattering) screens. By analyzing the interaction between two screens, astronomers can determine their relative positions. The strongest screen is very close to the explosion source, within 0/00000 light years from the explosion source/kloc-,which puts it in the galaxy where the explosion source is located. Only two things can leave such a trace on the signal: the nebula around the source or the ionized gas in the center of its galaxy.
In addition, the researchers also found that the radio emission of the fast radio burst has a flicker phenomenon similar to that of a star. This flicker phenomenon in radio band usually appears in the observation of pulsars. Dr. Li Yichao, National Astronomical Observatory of Chinese Academy of Sciences, analyzed the scintillation data of a pulsar in the direction of a fast radio burst, and showed that the fast radio burst, like pulsars, was partly caused by the interstellar medium of the Milky Way. It also shows that its explosion site should be within 3 billion light years.
100m Greenbank Telescope is the largest fully active radio telescope in the world. It is located in the National Radio Quiet Zone and the West Virginia Radio Astronomy Zone, which enables this extremely sensitive telescope to avoid unnecessary radio interference and make unique observations. The National Radio Observatory (NRO) is a facility of the National Science Foundation of the United States, and is operated by the United University Company under a cooperation agreement.
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