Broadband Imaging to Study the Spectral Distribution of Meteor Radio Afterglows
Broadband Imaging to Study the Spectral Distribution of Meteor Radio Afterglows
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DOI：
10.1029/2021ja029296
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发表时间：
2021-03
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影响因子：
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通讯作者：
S. S. Varghese-S.;J. Dowell;K. Obenberger;G. Taylor;J. Malins
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作者：
S. S. Varghese-S.;J. Dowell;K. Obenberger;G. Taylor;J. Malins
本文介绍了在塞维利亚塔长波阵列（LWA‐SV）站使用新型宽带成像仪对86颗流星射电余辉（MRAs）的观测结果。mra采用带宽高达20mhz的全天图像进行检测。我们用幂律和对数正态函数来拟合光谱。当采用幂律拟合时，光谱由平坦变为陡峭，由拟合得到的光谱指数分布在- 1.73处达到峰值。当与对数正态函数拟合时，频谱在30和40 MHz之间的频率上显示出周转率，并且似乎与光谱具有更好的函数拟合。我们将两种拟合方法的光谱参数与MRAs的物理性质进行了比较。我们观察到对数正态更替频率与mra海拔高度之间存在弱相关性。幂律拟合的谱指数与mra的物理性质没有很强的相关性。然而，mra的全宽半最大值持续时间与当地时间、入射角、亮度和母流星体的光学衍生动能有关。此外，mra的平均光度似乎与母流星体的动能和它们发生的高度有关。
We present observations of 86 meteor radio afterglows (MRAs) using the new broadband imager at the Long Wavelength Array Sevilleta (LWA‐SV) station. The MRAs were detected using the all‐sky images with a bandwidth up to 20 MHz. We fit the spectra with both a power law and a log‐normal function. When fit with a power law, the spectra varied from flat to steep and the derived spectral index distribution from the fit peaked at −1.73. When fit with a log‐normal function, the spectra exhibits turnovers at frequencies between 30 and 40 MHz, and appear to be a better functional fit to the spectra. We compared the spectral parameters from the two fitting methods with the physical properties of MRAs. We observe a weak correlation between the log‐normal turnover frequency and the altitude of MRAs. The spectral indices from the power law fit do not show any strong correlations with the physical properties of MRAs. However, the full width half maximum (FWHM) duration of MRAs is correlated with the local time, incidence angle, luminosity and optically derived kinetic energy of parent meteoroid. Also, the average luminosity of MRAs seems to be correlated with the kinetic energy of parent meteoroid and the altitude at which they occur.