论文标题
不可能的卫星 - 不可能造成的过境正时效应
Impossible moons -- Transit timing effects that cannot be due to an exomoon
论文作者
论文摘要
预计外容器将在其宿主行星上产生过境时序变化（TTV）。不幸的是，许多其他天体物理现象也是如此 - 最著名的是系统中的其他行星。在这项工作中，通过得出单个外显子产生的过境时序效应来引用还原荒谬的论点。我们的工作得出了三个关键的分析测试。首先，可能会利用一个事实，即外观中的TTV信号应伴有过境持续时间变化（TDVS），并且可以将TDV地板推导为最小预期的可变性水平。因此，TDV上限在此楼层以下的情况可以被杀死为Exomoon候选人。其次，提供公式用于估算当前不存在TDV时是否预计卫星是否被“杀人”，从而使社区能够估算是否值得首先推导TDV。第三，派生了TTV天花板，在上面，外部的外观绝对不能产生TTV振幅。这些工具应用于两到十千个开普勒对象的TTV和TDV目录，揭示了超过200个不能归因于月亮引起的情况。这些测试还应用于Exomoon候选Kepler-1625B I，该候选者舒适地通过了标准。这些简单的分析结果应提供一种快速拒绝推定的外部体并简化卫星搜索的方法。
Exomoons are predicted to produce transit timing variations (TTVs) upon their host planet. Unfortunately, so are many other astrophysical phenomena - most notably other planets in the system. In this work, an argument of reductio ad absurdum is invoked, by deriving the transit timing effects that are impossible for a single exomoon to produce. Our work derives three key analytic tests. First, one may exploit the fact that a TTV signal from an exomoon should be accompanied by transit duration variations (TDVs), and that one can derive a TDV floor as a minimum expected level of variability. Cases for which the TDV upper limit is below this floor can thus be killed as exomoon candidates. Second, formulae are provided for estimating whether moons are expected to be 'killable' when no TDVs presently exist, thus enabling the community to estimate whether it's even worth deriving TDVs in the first place. Third, a TTV ceiling is derived, above which exomoons should never be able to produce TTV amplitudes. These tools are applied to a catalog of TTVs and TDVs for two and half thousand Kepler Objects Interest, revealing over two hundred cases that cannot be due to a moon. These tests are also applied to the exomoon candidate Kepler-1625b i, which comfortably passes the criteria. These simple analytic results should provide a means of rapidly rejecting putative exomoons and streamlining the search for satellites.
