Candidates for Asteroid Dust Trails
Candidates for Asteroid Dust Trails
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小行星尘埃轨迹的候选者
DOI：
10.1086/505392
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
R. Walker
中科院分区：
文献类型：
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作者：
D. Nesvorný;M. Sykes;D. Lien;J. Stansberry;W. Reach;D. Vokrouhlický;W. Bottke;D. Durda;S. Jayaraman;R. Walker
不同来源对日周尘埃云（称为黄道云）的贡献可以从诊断观测中推断出来。我们使用斯皮策太空望远镜观察黄道附近黄道云的扩散热发射。在这些观测中发现了一些结构，包括以前已知的小行星尘埃带和彗星痕迹，这些尘埃带被认为是由最近的小行星碰撞产生的。有趣的是，检测到的两条尘埃轨迹（此处表示为 t1 和 t2）无法与任何已知的彗星联系起来。轨迹 t1 和 t2 代表的综合亮度比所有已知彗星轨迹的总和要大得多，因此可能是环日尘埃云的主要贡献者。我们利用斯皮策望远镜的观测结果确定了这些轨迹的轨道，并能够将它们与红外天文卫星 (IRAS) 在 1983 年发现的两条（“孤儿”或 II 型）轨迹联系起来。我们通过结合斯皮策和 IRAS 数据确定的轨迹 t1 和 t2 的轨道具有与主带小行星类似的半长轴、偏心率和倾角。因此，我们认为轨迹 t1 和 t2 是由最近（≲100 kyr 年龄）的小型、直径 ≲10 公里的主带小行星碰撞破裂产生的。
The contribution of different sources to the circumsolar dust cloud (known as the zodiacal cloud) can be deduced from diagnostic observations. We used the Spitzer Space Telescope to observe the diffuse thermal emission of the zodiacal cloud near the ecliptic. Several structures were identified in these observations, including previously known asteroid dust bands, which are thought to have been produced by recent asteroid collisions, and cometary trails. Interestingly, two of the detected dust trails, denoted t1 and t2 here, cannot be linked to any known comet. Trails t1 and t2 represent a much larger integrated brightness than all known cometary trails combined and may therefore be major contributors to the circumsolar dust cloud. We used our Spitzer observations to determine the orbits of these trails and were able to link them to two ("orphan" or type II) trails that were discovered by the Infrared Astronomical Satellite (IRAS) in 1983. The orbits of trails t1 and t2 that we determined by combining the Spitzer and IRAS data have semimajor axes, eccentricities, and inclinations like those of the main-belt asteroids. We therefore propose that trails t1 and t2 were produced by very recent (≲100 kyr old) collisional breakups of small, ≲10 km diameter main-belt asteroids.