TRANSIT OF EXOMOON PLASMA TORI: NEW DIAGNOSIS
TRANSIT OF EXOMOON PLASMA TORI: NEW DIAGNOSIS
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外月等离子环凌日：新诊断
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
G. Ballester
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文献类型：
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作者：
L. Ben;G. Ballester
在太阳系中，卫星的数量远远超过行星。开普勒数据库已被证明对火星质量的外行星探测非常敏感，但第一次搜索并不成功。在这里，我们使用粒子在细胞的代码来预测由卫星产生的等离子体环过境。尽管月球的体积很小，但其等离子体环的空间范围足以产生大量的凌日脉冲。该模型是用于解释哈勃空间望远镜早期的入口反射显然观察到的WASP-12 B和HD 189733 B紫外线过境没有一致的解释存在。对于HD 189733 B，需要一颗在行星前方经过1016 Rp并将1029个C ii离子s−1载入太空的系外卫星来解释观测到的C ii初步早期进入吸收。对于WASP-12 b，需要一个从行星前方经过106 Rp并每秒喷射1028 Mg ii离子的卫星来解释NUV早期进入吸收特征。有趣的是，HD 189733 B和WASP-12 B预测的卫星都在其行星的希尔球之外，这表明卫星（如果存在的话）不是在原地形成的，而是后来被捕获的。最后，我们的模拟表明，行星的极地地区和卫星的轨道位置之间的强电磁耦合，单极感应直流电路模型的预期结果。未来的观测应该测试我们的预测与一个潜在的机会，明确地检测到第一个exomoon等离子体环。
In the solar system, moons largely exceed planets in number. The Kepler database has been shown to be sensitive to exomoon detection down to the mass of Mars, but the first search has been unsuccessful. Here, we use a particles-in-cell code to predict the transit of the plasma torus produced by a satellite. Despite the small size of a moon, the spatial extent of its plasma torus can be large enough to produce substantial transit absorptions. The model is used for the interpretation of Hubble Space Telescope early ingress absorptions apparently observed during the WASP-12 b and HD 189733 b UV transits for which no consistent explanation exists. For HD 189733 b an exomoon transiting ∼16 Rp ahead of the planet and loading ∼1029 C ii ions s−1 into space is required to explain the tentative early ingress absorption observed for C ii. For WASP-12b, a moon transiting ∼6 Rp ahead from the planet and ejecting ∼1028 Mg ii ions per second is required to explain the NUV early ingress absorption feature. Interestingly, both HD 189733 b and WASP-12b predicted satellites are outside the Hill sphere of their planets, an indication that the moons, if present, were not formed in situ but probably captured later. Finally, our simulations show a strong electromagnetic coupling between the polar regions of planets and the orbital position of the moons, an expected outcome of the unipolar induction DC circuit model. Future observations should test our predictions with a potential opportunity to unambiguously detect the first exomoon plasma torus.