Sporadic meteor sources as observed by the Jicamarca high-power large-aperture VHF radar
Sporadic meteor sources as observed by the Jicamarca high-power large-aperture VHF radar
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Jicamarca 高功率大口径 VHF 雷达观测到的零星流星源
DOI：
10.1016/j.icarus.2006.11.006
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发表时间：
2007
期刊：
影响因子：
3.2
通讯作者：
F. Galindo
中科院分区：
文献类型：
--
作者：
J. Chau;R. Woodman;F. Galindo
我们提出，第一次，主要来源的零星流星推断从流星头回波获得的高功率大孔径雷达（HPLAR）。在Jicamarca HPLAR（南纬11.95°，西经76.87°，倾角1°）获得了这样的结果。观测是基于2001年11月至2006年2月期间在不到90小时的14天内发现的近170，000颗流星。据观察，具有太阳轨道的流星基本上来自六个先前已知的来源，即，北顶和南顶、阳离子、反阳离子、南北环，占观测值的91%。其余的109%代表观测速度大于太阳逃逸速度的流星，它们大多数都是太阳系外的。结果之前和之后，删除地球的速度和源模拟与二维高斯分布。总的来说，我们的结果与Jones和Brown报道的先前已知的来源非常一致[Jones，J.，布朗，P.G.，1993. Mon.没有R.宇航员。Soc. 265，524-532]主要使用多年来在不同地点收集的镜面流星雷达（SMR）数据。然而，我们发现位置和宽度略有不同，这可以根据两种技术的不同灵敏度和/或对我们的结果所需的校正来解释。例如，我们发现，南北顶点源是明确定义的，并且每个源都由两个同位高斯分布组成，一个几乎是各向同性的，宽度为10°，另一个在黄道经度上非常窄，在黄道纬度上很宽。这是首次报道这些窄宽度源。需要进行仔细的定量分析，以便能够比较用不同技术观测到的流星源的强度。我们还提出了选定的源的速度和初始高度分布。使用一个简单的角度灵敏度功能的组合地球大气雷达仪器，和高度选择标准，所产生的流星源是在更好的定性与SMR获得的结果。
We present, for the first time, the main sources of sporadic meteors as inferred from meteor-head echoes obtained by a high-power large-aperture radar (HPLAR). Such results have been obtained at the Jicamarca HPLAR (11.95° S, 76.87° W, 1° dip angle). Observations are based on close to 170,000 meteors detected in less than 90 h spread over 14 days, between November 2001 and February 2006. Meteors with solar orbits are observed to come from basically six previously known sources, i.e., North and South Apex, Helion, Anti-Helion, and North and South Toroidal, representing ∼91% of the observations. The other ∼9% represents meteors with observed velocities greater than the Sun's escape velocity at 1 AU, most of them of extra-solar origin. Results are given before and after removing the Earth's velocity and the sources are modeled with two-dimensional Gaussian distributions. In general, our results are in very good agreement with previously known sources reported by Jones and Brown [Jones, J., Brown, P.G., 1993. Mon. Not. R. Astron. Soc. 265, 524–532] using mainly specular meteor radar (SMR) data gathered over many years and different sites. However, we find slightly different locations and widths, that could be explained on the basis of different sensitivities of the two techniques and/or corrections needed to our results. For example, we find that the North and South Apex sources are well defined and composed each of them of two collocated Gaussian distributions, one almost isotropic with ∼10° width and the other very narrow in ecliptic longitude and wide in ecliptic latitude. This is the first time these narrow-width sources are reported. A careful quantitative analysis is needed to be able to compare the strengths of meteor sources as observed with different techniques. We also present speed and initial altitude distributions for selected sources. Using a simple angular sensitivity function of the combined Earth–atmosphere–radar instrument, and an altitude selection criteria, the resulting meteor sources are in better qualitative agreement with the results obtained with SMRs.