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arXiv 1306.3675astro-ph.EP
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月球表面反射的太阳风:远近观

Solar wind reflection from the lunar surface: The view from far and near

L. Saul, P. Wurz, A. Vorburger, D. F. Rodríguez M., S. A. Fuselier, D. J. McComas, E. Möbius, S. Barabash, Herb Funsten, Paul Janzen

摘要:

月亮在天空中显得明亮,是高能中性原子(ENA)的来源。这些ENA最近在一个广泛的能量范围内进行了成像,包括印度的Chandrayaan-1任务(CH-1)从月球表面附近,以及美国宇航局的星际边界探测器(IBEX)卫星从更远的地球轨道。这两组观测都表明,相对较大的一部分太阳风是以高能中性氢的形式从月球反射回来的。CH-1的角分辨率在月球表面的不同视角,使发射测量作为角度的函数。相比之下,IBEX不仅将月球的一个条带,而是整个象限视为有效的单个像素,因为即使在最近的方法中,它也不会超过天空的几度。在这里,我们使用CH-1测量的散射函数来模拟全球月球ENA发射,并将其与IBEX观测相结合。当包括角散射函数时,推导出的全局反射适度地更大(1.25倍)。这提供了一个稍微更新的IBEX估计AH = 0.11 +/- 0.06的全球中和的散射,这是25%以上的先前值0.09 +/- 0.05,基于一个假设的均匀散射分布。

英文摘要:

The Moon appears bright in the sky as a source of energetic neutral atoms (ENAs). These ENAs have recently been imaged over a broad energy range both from near the lunar surface, by India's Chandrayaan-1 mission (CH-1), and from a much more distant Earth orbit by NASA's Interstellar Boundary Explorer (IBEX) satellite. Both sets of observations have indicated that a relatively large fraction of the solar wind is reflected from the Moon as energetic neutral hydrogen. CH-1's angular resolution over different viewing angles of the lunar surface has enabled measurement of the emission as a function of angle. IBEX in contrast views not just a swath but a whole quadrant of the Moon as effectively a single pixel, as it subtends even at the closest approach no more than a few degrees on the sky. Here we use the scattering function measured by CH-1 to model global lunar ENA emission and combine these with IBEX observations. The deduced global reflection is modestly larger (by a factor of 1.25) when the angular scattering function is included. This provides a slightly updated IBEX estimate of AH = 0.11 +/- 0.06 for the global neutralized albedo, which is 25 % larger than the previous values of 0.09 +/- 0.05, based on an assumed uniform scattering distribution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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