Multiple first discovery!Nature: Chinese "Sky Eye" shoots a "blockbuster" for mysterious signals

Text ｜ "China Science News" reporter Feng Lifei

Fast radio storm and host galaxy art imagination. The world's largest single -caliber radio telescope China "Tianyan" (bottom left) and the highest single -caliber optical telescopic telescope (upper right) with the highest space resolution to undertake the research and observation task. Yu Jingchuan, Fu Hai draws

In 54 days and 82 hours, scientists used the "mysterious signal" that died only ten seconds outside the Milky Way -the fast radio storm (FRB) 20201124A shot a "blockbuster". Related research results were published in "Nature" on September 22.

The energy of radio bands that instantly erupted in the rapid radioactive storm in a few milliseconds is equivalent to the sum of the total global total power generation. Since the first discovery in 2007, scientists have found thousands of such incidents so far. But what the origin of their origin is not very certain.

Scientists conducted dynamic monitoring of nearly 2,000 outbreaks of this off -river signal and obtained several international first important discoveries. "We found that it comes from a place where the star of a host galaxy is not so dense, where the magnetic field changes very strong." Li Keja, a professor of the paper, professor of Peking University, and researcher at the National Astronomical Observatory of the Chinese Academy of Sciences.

"Using the world -class" Sky Eye "telescope developed by our country, the first phenomenon that others have not yet seen have been seen. This is exciting and the charm of scientific discovery." He is honored to participate in the early debugging of FAST since 2017 and participate in related research after the completion of large devices.

On the same day, Wang Fayin, co -author of the paper and professor of astronomy at Nanjing University, was also published in another study published in "Nature -Communication". In addition to neutron stars), it provides evidence for the potential power source of the "double star" of fast -moving electrical storms.

Capture strange phenomenon

FRB 20201124A is an extra -river signal discovered by the Canadian hydrogen intensity surveying and mapping experiment (Chime) telescope in 2020.

"This big field telescope is very good at seizing new fast radio violence. After finding that this signal is active, we immediately start to follow up." Zhu Weiwei told the Journal of Science of China that this is a case of international cooperation and information sharing of astronomy. Just as Wang Pei, deputy researcher of the National Observatory of the Chinese Academy of Sciences, used FAST and others to discover another fast radio violence FRB 20121102A repeatedly appeared and shared with international peers in "Astronomy Briefing". The celestial bodies seize the new phenomenon.

From the two months from April 1st to June 11th, 2021, scientists use Fast to carry out the continuous observation of FRB 20201124A every day.

"Just like making movies, watching its physical evolution through radio." Zhang Bing, a co -communication author and a professor at Las Vegas, University of Nevada University in the United States, said that with the rotation and revolution of the earth, there are more than two of these two. In the month, the observation time slowly moved from 4 pm to the morning, and the last observation was 6 o'clock in the morning.

According to reports, it is not difficult to calculate the observation time, as long as it "runs twice by the model" on the computer. The complex is a large amount of data obtained by analyzing and processing in the process -1863 explosive dynamic pulse signals observed at 54 days and 82 hours. Such a high frequency explosion also makes the incident one of the most active repeated violence. To understand what these data explain, researchers need to develop new theoretical models.

"The manuscript was received in July this year. Compared with the observations for more than two months, most of the time we have been analyzed in the past year and a half, what information obtained by analyzing." Li Keja said.

What makes researchers happy is that they eventually observe many rapid radio violations that have not been discovered internationally.

This includes the strange evolution of Faraday rotation for the first time, that is, the irregular short -term label evolution occurred in Faraday rotation in the first 36 days, and it was almost unchanged in the subsequent 18 days. The phenomenon of extinguishing is, from the state of maintaining a high explosion to the sudden extinguish within 72 hours; for the first time, it was detected that all high -circuit polarization pulses that were significantly different from all the rapid radio electrical violence before, and the maximum value reached 75%; the polarization was also measured for the first time. With the phenomenon of electromagnetic waves.

"These phenomena show that the environment of a astronomical unit (that is, the distance from the sun to the earth) around the FRB 20201124A is very complicated and dynamically evolved." Li Keja said.

He explained to the "China Science News" that Faraday's rotation volume can be used to understand the strength of the magnetic field in the environment, and the changes observed show that the magnetic field environment around the fast radio violence has changed drastically. At the same time, through polarizing oscillations, they believe that the surrounding magnetic field has reached Gaussian order or above.

Sighting the mysteries of origin

The research also used international cooperation to make the Chinese and Western telescope "double -sword combination", which complementary advantages in radio bands and optical bands, providing new evidence for the host environment and theoretical mechanism that can be generated by fast radio violence.

"In the observation of the FRB 20201124A, we also used the Kok 10m optical telescope in Hawaii to observe its host galaxy. For the first time, the structure of the host galaxy was distinguished, revealing the galaxy environment on hundreds of light years around it. . "The author of the paper and the professor of Peking University told the Journal of Science of China. According to reports, the research team used spectrals to observe the accurate red shift of the host galaxy, and it is estimated that it is about 1.5 billion light years from the earth. Due to the influence of atmospheric turbulence, it is not easy to see such a distant host galaxy. The previous images can only see a fuzzy ball and cannot distinguish any structure. By carried out international cooperation with astronomers such as Fu Hai, a professor at the University of Aiwa University, and adopted the Kok Tele -telescope with adaptive optical technology equipped with advanced laser, the research team overcame the adverse effects. Essence

"This is a galaxy of the galaxy -rich, metal -rich galaxy." Chen Ping, co -author of the paper and Ph.D. in Peking University, introduced to the "Chinese Science News" that the so -called "stick galaxy" refers to a " The stick -shaped structure passes through the vortex galaxy in the center of the galaxy. Studies have found that the source of fast radio storms in this study is not on the "stick", nor is it on the "vortex" spin arm, but is between the spin arm and the distance from the center of the galaxy. area.

What is the scientific significance of understanding the structure of the host galaxy and the galaxy environment around the fast radio violence?

In the past, the host galaxy of the repetitive fast radio storms taken by scientists before, whether it is a dwarf galaxy smaller than the galaxy, or a vortex galaxy similar to the Milky Way, is mostly near the intensive birthplace of a large number of young stars. To this end, some scientists have proposed hypothesis that fast radio violence may be related to young magnetic stars formed after the super -bright supernova or gamma rays caused by the extreme explosion of large -quality stars.

"But our research shows that the repeated violence is in a relatively ordinary galaxy environment." Dongsubop said that this means that this duplicate galaxy environment does not support the above hypothesis.

In the research published in "Nature -Communication", Wang Fain and collaborators have a model analysis of the potential power sources of FRB 20201124A based on observation data.

So far, there are more than 60 models of rapid radio violations established by scientists, such as magnetic stars, neutron stars, or neutron stars and asteroid collisions. In 2020, Chinese and foreign scientists first determined that the rapid radio violence FRB 200428 originated from magnetic stars; but most of the fast radio violence came from outside the galaxy, and their origin has not been verified.

Wang Fayin and partner analysis found that the Ferradi rotation of the FRB 20201124A changes the symbol, indicating that the surrounding magnetic field changed the direction, which is similar to the PSR B1259-63/LS 2883 double star in the galaxy. "This shows that it may come from a double star system composed of a magnetic star and be star (a type B star B in the spectrum)." He told the China Science Journal.

They also found that the incident was the first duplicate fast radio violence with the longest polarization and duration. "Generally, the average time of radio power is only a few milliseconds. This time, it can reach about 15 milliseconds, which is higher than an order of magnitude." Wang Fayin compared to comparison. The scattering of scattering causes the duration of rapid radioactive storms.

In addition, its Faraday rotation volume has changed significantly and is accompanied by refunds, which may be caused by different substances and magnetic fields on the disk, which causes the Faradie rotation value in different directions to be different.

According to reports, the model can explain the Faraday rotation evolution of the latest three fast radioactive storms (FRB 190520B, FRB 180916 and FRB 220529). "This model may originate from the double -star system to give strong evidence that some fast radio violence may originate from the double -star system, which has a very important value for this field." A reviewer commented.

Approach the truth

After the first fast radio violence was discovered in 2007, scientists had estimated that a radio violence could only be seen every 10 years. However, in the past few years, the systemic and large -scale development of the telescope of Dazhong Field has made the changes in the field of research a thousand miles a day. There are hundreds of rapid radioactive storms in the world, and thousands of found have reached thousands of.

"Thanks to the great power of Fast, in the past few years, Chinese scientists have continuously obtained new discoveries in the field of rapid radio violence research, and have been active in the forefront of the world." Zhu Weiwei said.

However, he said that there are still many questions waiting to answer. For example, what is the origin of FRB? Why do so many explosions occur? This needs to combine astronomical observation with theoretical modeling, constantly discover new phenomena and possibilities, and approach the truth step by step.

In order to achieve this goal, Li Kejia said that in addition to Fast, infrastructure such as "Hui Eye" hard X -ray space telescope and "Teana" telescope experimental array will gradually solve the problem of insufficient observation capabilities in astronomical observation."Looking forward to our nearly 100 people's cooperation teams can rely on FAST to guide more international joint observations, produce more important results in the next few years, find true sources, and contribute to understanding this violent celestial physical phenomenon." He said.Wang Fayin recommends strengthening the cultivation of rapid radio violence research talents.He told reporters that most researchers in this field have been transferred from pulse star research, and the overall strength of the talent team is still insufficient.

Related thesis information:

https://doi.org/10.1038/s41586-022-05071-8

https://doi.org/10.1038/s41467-022-31923-y

"China Science News" (2022-09-23 The 1st edition of the news)

Edit | Zhao Lu

Capture | Zhihai

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