Meteoroid velocity distribution derived from head echo data collected at Arecibo during regular world day observations
Meteoroid velocity distribution derived from head echo data collected at Arecibo during regular world day observations
复制标题
流星体速度分布源自阿雷西博定期世界日观测期间收集的头部回波数据
DOI：
10.5194/acp-4-947-2004
复制
发表时间：
2004
影响因子：
6.3
通讯作者：
M. Sulzer
中科院分区：
文献类型：
--
作者：
M. Sulzer
抽象的。我们报告的观测和分析电离闪光与流星衰变（所谓的头回波）检测的阿雷西博430兆赫雷达在定期电离层观测在春分和秋分。这两个周期允许在黎明时事件率最大时指向黄道面上方和附近。通过对数千个事件的观测，可以对结果进行统计解释，结果表明，如以前所报告的那样，观测到的流星体有很强的来自顶点的倾向（Chau和Woodman，2004年）。速度分布与Janches等人（2003 a）的结果一致，但在这些观测中使用的方位扫描提供了一个新的视角。我们构造了一个简单的统计模型，它以流星速度为输入，以雷达视线速度为输出。目的是解释速度分布中最快的部分。由于从测量中解释的速度分布相当狭窄，约为60 km s-1，是地球在其轨道上速度的两倍，这与阿雷西博雷达看到的许多流星体在绕太阳的轨道上以与地球相似的参数移动的解释是一致的，但在逆行方向上。然而，从波束摆动雷达实验中获得的方向信息和速度一起为这种解释提供了证据。从测量的速度分布的某些方面来看，这并不是一个完整的描述，即使是对分布的快速部分，它当然也没有说明Janches等人（2003 a）首次描述的慢速部分。此外，我们不能对整个尘埃种群做出任何结论，因为可能存在选择效应，将观测限制在种群的一个子集。
Abstract. We report the observation and analysis of ionization flashes associated with the decay of meteoroids (so-called head echos) detected by the Arecibo 430 MHz radar during regular ionospheric observations in the spring and autumn equinoxes. These two periods allow pointing well-above and nearly-into the ecliptic plane at dawn when the event rate maximizes. The observation of many thousands of events allows a statistical interpretation of the results, which show that there is a strong tendency for the observed meteoroids to come from the apex as has been previously reported (Chau and Woodman, 2004). The velocity distributions agree with Janches et al. (2003a) when they are directly comparable, but the azimuth scan used in these observations allows a new perspective. We have constructed a simple statistical model which takes meteor velocities as input and gives radar line of sight velocities as output. The intent is to explain the fastest part of the velocity distribution. Since the speeds interpreted from the measurements are distributed fairly narrowly about nearly 60 km s-1, double the speed of the earth in its orbit, is consistent with the interpretation that many of the meteoroids seen by the Arecibo radar are moving in orbits about the sun with similar parameters as the earth, but in the retrograde direction. However, it is the directional information obtained from the beam-swinging radar experiment and the speed that together provide the evidence for this interpretation. Some aspects of the measured velocity distributions suggest that this is not a complete description even for the fast part of the distribution, and it certainly says nothing about the slow part first described in Janches et al. (2003a). Furthermore, we cannot conclude anything about the entire dust population since there are probably selection effects that restrict the observations to a subset of the population.