A rapid radio burst is an instantaneous burst of radio waves in the universe that usually last only a few milliseconds, but release the same amount of energy that the sun releases in a day or even a year. They often “god dragons see no end”, appear once, there is no trace. As a new “network celebrity” in astronomy in recent years, the international scientific community has put forward dozens of “reasonable explanations” for the origin of rapid radio storms, such as strong magnetic field neutranes, highly active galactic cores, collisions between objects, and even scientists suggest that they are signals from extraterrestorial civilizations.
Author: Princess Feng
But evidence of direct observation has been lacking.
In three papers published in Nature on November 5th, Chinese and foreign scientists observed several satellites and ground-based telescopes that a magnetic star in the Milky Way was the origin of a rapid radio storm observed this year.
This is the first time that humans have determined the origin of a rapid radio storm, and the first time a rapid radio storm has been observed in the Milky Way.
The rapid radio storm released by the magnetic star is painted by LiKoga
The magnetic star “engine” has been confirmed
On April 28 this year, a radio signal quickly crossed the universe and was captured by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope and the U.S. Transient Astronomical Radio Emission Survey 2 (STARE2) telescope.
According to the time of discovery, it was named “FRB200428”.
Although it flashed only a thousandth of a second, scientists determined its origin by measuring multiple frequency bands — SGR 1935 plus 2154, a magnetic star in the Milky Way that is active.
Scientists have long speculated differently about the source of rapid radio storms.
Among them, the theory of magnetic star drive is widely supported. Magnetic stars are highly magnetized young neutranes (the remains of dense stars after supernova explosions) with a surface magnetic field of more than 1014 Gaussians, and their decay is thought to power a range of high-energy phenomena such as radio bursts, X-rays, and γ-rays.
Taking the active magnet found as an example, Danielle Michille of the CHIME team says its magnetic field is strong enough to “squeeze an atom into a pencil.”
So does this discovery mean that the rapid radio storms are all from magnetic stars? Zhang Bing, a professor at the University of Nevada, Las Vegas, told China Science daily that one extreme view is that all rapid radio storms in the universe are caused by magnet stars, and the other is that there is more than one origin that does not negate “the creativity of nature”.
According to the introduction, there are more than 50 related models of the origin of rapid radio storms, the mainstream theory points to large dense objects, in addition to magnet stars, there are neutrane star collision, neutrane star and black hole collision or black hole collision, such as the resulting “disaster denaturation” rapid radio storm, non-mainstream models have extraterrestorial civilization signals.
However, none of this has been verified.
“The richness of the rapid radio storm model reflects a lack of physical constraints, largely because past outbreaks have been found outside the Milky Way galaxy, far away.” Li Li, a researcher at the National Observatory 菂 Chinese Academy of Sciences, told the China Science Daily. On the same day, he and Zhang Bing and more than a dozen domestic and foreign partners from Peking University and Peking University published the results of the monitoring of the magnet star by China’s “Sky Eye” 500-meter sporadic radio telescope (FAST) in Nature. “The discovery of the Hanoi radio explosion and the in-depth observations of it by a number of devices, including the ‘China Sky Eye’ and ‘Eye’ satellites, provide unprecedented information.” He said.
Rare Hanoi signal
In sync with foreign scientists, the FAST team has been closely monitoring the dynamics of the magnet star SGR 1935 plus 2154 with the “Sky Eye”.
“From April 15th to 28th, we monitored for a total of eight hours over four periods whether it could produce a rapid radio storm, or something like that.” Lin Lin, the study’s first author and a lecturer in the Department of Astronomy at Beijing Normal University, told China Science Daily.
Unfortunately, fast observation windows missed FRB 200428.
Nevertheless, it records sensitive monitoring data during high-energy bursts of magnetic stars, especially 29 soft γ-ray bursts, which helps to understand the background that causes rapid radio bursts.
“There are a lot of high-energy bursts of magnetic stars, isn’t all high-energy bursts producing rapid radio bursts?” What kind of physical mechanism will be produced? Our observations give exactly the background to which it is generated. “
The study’s co-author, Li Kega, an associate professor at Peking University’s Institute of Astronomy and Astrophysics, said.
The FAST team’s research shows that most magnet stars produce high-energy bursts, such γ bursts of radiation, and do not produce rapid radio bursts.
What’s the reason? In this paper, they discuss several possibilities: rapid radio bursts have a more accurate flow than high-energy emissions, most of which miss the Earth;
This is the first time that Chinese and foreign teams have demonstrated that magnet stars can produce rapid radio storms up close within the Milky Way.
“If a rapid radio storm comes from a magnet star, which is associated with star formation, and the Milky Way doesn’t have ‘enough scary’ star formation, it’s less,” Christopher Bochenek of the California Institute of Technology, a co-author of the STARE2 team, explained in an interview with China Science.
It is understood that the total energy of FRB200428 observed this time is three orders of magnitude lower than the brightness of the previously observed rapid radio storms outside the river.
Experts say the discovery of radio pulses in Hanoi has greatly expanded the cognitive space and helped to understand the secrets behind the signals.
International Collaboration China Sync
Start late and make rapid progress.
The origin of rapid radio storms and related research have become the new “network celebrities” in astronomy.
In July 2001, a bright radio storm that lasted 5 milliseconds arrived at Australia’s Parkes telescope, and in 2007 it was confirmed by Duncan Lorimer, an astronomer at the University of West Virginia, as the only such eruption of its kind.
It wasn’t until multiple signals were discovered in 2013 that astronomers believed it was a truly astrophysical event and named it a rapid radio storm.
According to reports, the rapid radio storm found has reached 1000 magnitude.
“About every six months, people’s understanding of rapid radio storms takes a huge leap forward.” Zhang Bing wrote in a guest review published in Nature at the same time that the boom in the sector was also reflected in the steady growth of publications and citations, which had surpassed earlier levels in gamma-ray bursts.
Nevertheless, there are still many outstanding key questions about the origin of rapid radio storms.
For example, do all rapid radio storms repeat them? Do they come from outside the magnet star “engine”? How do magnets produce rapid radio storms? Answering these questions is not easy.
On the plus side, the international astronomical community is conducting increasingly close collaborative observations, as evidenced by the discovery of the origin of FRB 200428.
“This suggests that when teams of international scientists come together to study a phenomenon in different ways, it gives us a deeper understanding of it.”
Bochenek said that in addition to FAST, CHIME, STARE2, China’s “eye-opening” X-ray satellites, the BOOTS telescope array in China, Spain and New Zealand, and the U.S. LCOGT telescope also played an important role in the discovery.
In China, open astronomical research equipment is attracting in-depth cooperation between researchers from across research institutions and disciplines.
“We have world-class scientific devices, such as FAST calibres, high sensitivity, and the ability to see faster radio storms near darker and deeper in the universe, which no one else can do.” Lynn said.
At the same time, she was impressed by the efficient collaboration between experts in fast joint observation teams, from observation to data processing to theoretical interpretation, and the smooth communication between the team and the Eye-catching team.
Launched this year as a five-year FAST priority program, the Radiostorm Observation Project will provide further in-depth observations of radiostorm events, their origin and trace their radiation.
“This is an important frontier direction, and observations of rapid radio storms deep in the universe will add a new tool to understanding the universe. FAST is making a unique and important contribution. “FAST chief scientist Lee 菂 said.
In this regard, in addition to the “sky-eye” “eye”, the current long-band radio telescope array “Tianqi” and gravitational wave detector “Tianqin” “Ali” and other future will also join the rapid radio storm collaborative observation array, through multi-band coordination, to understand the secret of this mysterious “cosmic radio waves.”