Sporadic micro-meteoroid source radiant distribution inferred from the Arecibo 430 MHz radar observations
Sporadic micro-meteoroid source radiant distribution inferred from the Arecibo 430 MHz radar observations
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根据阿雷西博 430 MHz 雷达观测推断的零星微流星体源辐射分布
DOI：
10.1093/mnras/stac1921
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发表时间：
2022
影响因子：
4.8
通讯作者：
Huang, Tai-Yin
中科院分区：
文献类型：
--
作者：
Li, Yanlin;Zhou, Qihou;Urbina, Julio;Huang, Tai-Yin
本文首次利用位于波多黎各的阿雷西博430mhz非相干散射雷达（ISR）获得了零星流星辐射密度分布的结果。尽管使用阿雷西博ISR进行了许多流星研究，但流星体的辐射密度分布仍然是一个谜，因为阿雷西博雷达无法测量矢量速度。设计了一种基于动态规划和随机梯度下降的数值轨道模拟算法，求解阿雷西博观测到的流星散射辐射密度和相应的速度分布。该算法的数据集包括2009年至2017年阿雷西博天文台观测到的25万多颗流星。从我们的结果中可以识别出六个已识别的零星流星源中的五个。没有明确可识别的南顶点来源。相反，在黄道纬度+/−30°之间分布广泛，峰值密度位于北顶点方向。我们的结果还表明，阿雷西博雷达对直接进入或垂直于天线波束的流星不敏感，但对到达角度在30°到60°之间的流星最敏感。我们的分析表明，当考虑到撞击概率时，阿雷西博雷达观测到的流星体中约有75%在顺行轨道上运行。大多数逆行流星体在倾斜的低偏心率轨道上运行。
This work presents the result of sporadic meteor radiant density distribution using the Arecibo 430 MHz incoherent scatter radar (ISR) located in Puerto Rico for the first time. Although numerous meteor studies have been carried out using the Arecibo ISR, meteoroid radiant density distribution has remained a mystery as the Arecibo radar cannot measure vector velocity. A numerical orbital simulation algorithm using dynamic programming and stochastic gradient descent is designed to solve the sporadic meteoroid radiant density and the corresponding speed distributions of the meteors observed at Arecibo. The data set for the algorithm comprises over 250000 meteors from Arecibo observations between 2009 and 2017. Five of the six recognized sporadic meteor sources can be identified from our result. There is no clearly identifiable South Apex source. Instead, there is a broad distribution between +/−30° ecliptic latitude, with the peak density located in the North Apex direction. Our results also indicate that the Arecibo radar is not sensitive to meteors travelling straight into or perpendicular to the antenna beam but is most sensitive to meteors with an arrival angle between 30° and 60°. Our analysis indicates that about 75 per cent of meteoroids observed by the Arecibo radar travel in prograde orbits when the impact probability is considered. Most of the retrograde meteoroids travel in inclined low-eccentricity orbits.