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“In the field of radio astronomy, we have entered the first team”
—— “China Sky Eye” has achieved a number of important scientific achievements
The observation service exceeded 5,200 aircraft hours, almost double the expected target; cumulatively discovered more than 240 pulsars; published more than 40 high-level papers based on observational data … This is the 500-meter caliber known as the “China Sky Eye” The achievements of the spherical radio telescope (FAST) since its inception.
On November 4, the National Astronomical Observatory of the Chinese Academy of Sciences held a press conference to introduce that the “China Sky Eye” is operating stably and reliably and has achieved a number of important scientific achievements. Among them, the research results of fast radio bursts “China Sky Eye” have recently been published in the international scientific journal “Nature”. The smooth operation of the “China Sky Eye” has made China’s relevant scientific research teams rapidly become the main research force of international rapid radio storms.
“Astronomy is a science that relies heavily on observing equipment. Without observing equipment, you can only conduct research based on other people’s data.” Wu Xiangping, an academic at the Chinese Academy of Sciences and director of the FAST Scientific Committee, said at the press conference: “With excellent powerful tools, we are The state of the field of international astronomy is different … In the field of radio astronomy, we have joined the first team. “
Research on the frontiers of astronomy is no longer based on “second-hand data”
In the vast universe, there are often radio waves striking, flashing for only a few milliseconds. Astronomers have been trying to find the truth: who sent these waves? What information does an electrical wave contain that flickers so fast?
In 2017, astronomers captured a radio burst with a timescale of milliseconds and it was repeated several times within a few hours. Astronomers used the world’s many large radio telescopes to jointly detect fast positioning and eventually located a repeating source of radio flares in a galaxy 3 billion light-years away in the depths of the universe.
However, these studies have not been linked to China for a long time. “In the past, because there were no large radio telescopes, Chinese astronomers couldn’t get first-hand data, so most of the research in this frontier field was theoretical research,” said Chang Jin, an academic at the Academy. China Science and Director of the National Astronomical Observatory.
In January 2020, “China Sky Eye” passed national acceptance. This reflective surface is equivalent to about 30 standard football fields, the world’s most sensitive single-aperture radio telescope, vastly expanding humanity’s field of view and ultimately giving Chinese astronomers the opportunity to be at the forefront of radio astronomy research.
With the help of the “Chinese Sky Eye”, Chinese astronomers have discovered a new physical phenomenon of cosmic millisecond radio bursts: recently, the research team of Peking University professor and researcher at the National Astronomical Observatory Li Kejia used the “Chinese Sky Eye” to detect a fast and repetitive radio burst. For the first time, the radiation from this repeating storm was found to have very rich polarization characteristics. This observation provides new information about the origin of the radiation from fast radio storms; Dr. Lin Lin from Beijing Normal University, Dr. Chunfeng Zhang from Peking University, Dr. Pei Wang from the National Astronomical Observatory, etc. The team used the “Chinese Sky Eye” to make joint multiband observations of the repetitive soft gamma-ray bursts from the Milky Way magnetar, and found that the repetitive soft gamma-ray bursts have a weak correlation with the fast repetitive radio bursts. .
If there is no “Chinese eye to the sky,” Chinese astronomers will still have to rely on “second-hand information” from other people to research these border fields.
“We are sure we can find a thousand pulsars”
The study of fast radio bursts is just a microcosm. “With improved performance, the scientific potential of the ‘China Sky Eye’ is gradually emerging.” Chang Jin pointed out that the ultra-high sensitivity of the “China Sky Eye” has great potential for transient radio sources, which are expected to reach nanohertz in a short period of time. Gravitational waves detect and capture the original gravitational waves during the Big Bang period and provide data support to study the physical process at the original Big Bang time. At the same time, it also has the ability to extend China’s deep space exploration and communication capabilities to the edge of the solar system to meet major national strategic needs.
Gravitational wave detection is a hot topic in the astronomy circle in recent years. Through long-term monitoring of millisecond pulsars, a certain number of millisecond pulsars are selected to form a time matrix, which can detect low-frequency gravitational waves from supermassive double black holes and other celestial bodies. “Thanks to the high sensitivity of the China Sky Eye, we have increased the precision of the pulsar’s timing by at least an order of magnitude, which is expected to allow humanity to have the ability to detect NHz gravitational waves for the first time. can say that we are already on the way to achieve great results. “On the way of escalation,” said Chang Jin.
Pulsars are named after they continuously emit electromagnetic pulses and are an unknown celestial body. According to Chang Jin, the number of pulsars discovered by the “China Sky Eye” exceeded 240. Among them, the globular star cluster M92 is a millisecond pulsar with an eclipse phenomenon. This is the first millisecond pulsar discovered in M92. The close orbit and larger mass of the companion star indicate that the companion star’s material is augmented by pulsars. With the high sensitivity of the “Chinese eye of the sky”, the obscuring phenomenon of the pulsar signals caused by the occlusion of the companion star and its stellar wind and the delayed arrival time of the pulsar signal caused is clearly observed by the wind of the companion star. Pulse binary stars with these special phenomena are called the “red back spider” system in astronomy. This discovery was selected by the American Astronomical Society as an outstanding research result.
An important task of the “China Sky Eye” in the future is to search for more pulsars. “We are sure we can find a thousand pulsars.” Han Jinlin, the principal investigator at the National Astronomical Observatory, said the closest pulsars have been discovered abroad and we can only look for more distant ones. “If there is, we won’t miss anyone.”
“China Sky Eye” will be open to scientists from around the world
In fact, the advanced measurement technology of “China Sky Eye” is much more than the telescope itself and has important application prospects in other fields. For example, in high-precision geological and mining exploration, inertial components and satellite navigation fusion technology can be used to provide a high-precision azimuth attitude and position reference for gravity measurement; In marine surveying and mapping, inertial components and sonar and other measurement technologies are integrated to perform seabed prospecting and mapping. , Establish high precision time-space and attitude benchmarks for machinery and equipment operating in the exploration area.
At present, the “China Sky Eye” has been officially opened to domestic astronomers, and the facilities are stable and reliable. In the last year, more than 5,200 hours of observation have been observed and completed. In February 2020, “China Sky Eye” officially launched the five “priority and main projects” selected by the scientific committee. Almost 200 scientific users have started to use and process “China Sky Eye” scientific data.
In April 2020, the “China Sky Eye” Observation Time Allocation Committee began to apply for free application projects from the national astronomical community. So far, more than 170 applications have been received. The total application time is about 5,500 hours. Actual approval of 1,500 machine hours is only 30.% Can be supported. It can be seen that the “China Sky Eye” observing time competition is quite fierce.
Although fierce, the “China Sky Eye” will also face more scientists. “Next year, the ‘China Sky Eye’ will open to the world. Scientists around the world can use the world’s largest radio telescope to jointly explore the mysteries of the universe, promote the progress of human civilization, and build a community of shared future for humanity. ” Wu Xiangping Announced at the press conference.
The same space, the same house. In the future, “China Sky Eye” will bring more surprises from space.
(Our newspaper, Beijing, November 4, by our reporter Chen Haibo)
