Important discovery!, The Chinese Eye Pulse | Discovery
The "big pot" in Guizhou has been discovered again. Using the Chinese celestial eye, Chinese astronomers have discovered a new form of pulsar radiation - short pulse radiation, and revealed the physical fact that the magnetospheric structure of pulsars remains basically unchanged when radiation is on the verge of extinction. More importantly, this pulsar radiation pattern is difficult to observe by other radio telescopes internationally. The related research results were published online on August 18th in the journal Nature Astronomy.
Panoramic view of China's Heavenly Eye. Photo by Xinhua News Agency reporter Ou Dongqu
Generally speaking, pulsars periodically emit electrical signals during their rotation. However, in certain cycles, the radiation of some pulsars will completely extinguish, a phenomenon known as pulse nulling by astronomers. "After the pulsar radiation is extinguished, there is no radiation at all, and its magnetospheric structure and physical characteristics are difficult to detect, so it is difficult to determine the physical mechanism of pulse nulling." Han Jinlin, the corresponding author of the paper and a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, said frankly.
Coincidentally, during the use of FAST for pulsar search, the research team discovered a very special pulsar B2111+46 in a massive amount of data. "We originally thought that this pulsar had undergone pulse nulling, but upon closer examination, we found that it still had scattered weak and narrow pulse widths. We referred to such pulses as dwarf pulses," explained Han Jinlin.
Subsequently, the research team conducted two hours of verification observation on this pulsar and obtained over 100 dwarf pulses. These pulses differ significantly from normal pulses in terms of pulse intensity and width distribution, forming an independent radiation population. Meanwhile, FAST conducted precise polarization measurements on these short pulses. The results indicate that compared with normal pulses, the magnetic layer structure in the radiation region of short pulses remains largely unchanged, but short pulses are more prone to strong flow in the high-frequency band.
"The pulsar B2111+46 is relatively old and already located in the 'Death Valley' of the pulsar. Therefore, the reason for pulse nulling is likely due to the radiation instability caused by the insufficient induction potential and particle acceleration energy of the old pulsar. Han Jinlin said that the normal pulse of the pulsar is emitted by steadily accelerating a large number of charged particles and producing a large number of 'thunderstorm' particle droplets, while the short pulse is generated by one or a few particle droplets formed by the dying pulsar in a fragile and unstable state.".
The research team also detected a small amount of dwarf pulses in the pulse nulling state of several other pulsars. The discovery of this extremely weak radiation mode has opened up a new window for studying the radiation problem of pulsars, and is of great scientific significance for revealing the physics of pulsar magnetosphere and its extreme plasma environment.
