基于PSP观测的行星际Ⅲ型射电爆发的研究进展

Research Progress on Interplanetary Type III Radio Bursts Based on PSP Observations

与太阳射电爆发相比,通常认为频率较低的行星际射电爆发产生于远离低日冕的行星际空间.地球电离层的截止导致地基设备无法对其进行观测.美国国家航空航天局(National Aeronautics and Space Administration,NASA)发射的帕克太阳探测器(Parker Solar Probe,PSP)是迄今为止距离太阳最近的空间探测器.其搭载的射电频谱仪能够对10 k Hz-19.17 MHz频段范围内的射电辐射进行观测.PSP能够靠近甚至可能穿越行星际III型射电爆发的辐射源区,因此使用PSP对行星际射电爆发进行观测具有前所未有的优势.简要介绍了目前为止使用PSP的射电观测数据对行星际III型射电爆发的多方面研究,包括爆发的发生率、偏振、散射、截止频率、可能的辐射机制和相关的辐射源区等方面的研究进展,并讨论了其未来的研究前景.

Compared to solar radio bursts,interplanetary(IP)radio bursts with lower radiation frequencies are generally believed to originate in the interplanetary space far from the low corona.The cutoff by Earth’s ionosphere makes the ground-based observations for it impossible.Parker Solar Probe(PSP),launched by the National Aeronautics and Space Administration(NASA)to explore the Sun with the closer heliocentric distance than any previous spacecraft,provides an opportunity to study the low-frequency radio burst.The radio spectrometer it carries can observe radio radiation in the frequency range of 10 kHz-19.17 MHz.PSP can approach the radiation source region of the IP type III radio burst.Therefore,it has an unprecedented advantage to observe the interplanetary radio bursts.This paper reviews the studies about type III radio bursts observed by PSP so far.These studies include the occurrence rate,polarization,scattering,cutoff frequency,possible radiation mechanisms,and related radiation source regions of radio bursts and so on.Finally,future research prospects are discussed.