论文标题
半径间隙的两个视图和光曲线拟合的作用
Two Views of the Radius Gap and the Role of Light Curve Fitting
论文作者
论文摘要
最近，几个小组解决了一个差距，将地球和海王星之间的行星分叉分为两个人群。此功能的位置和深度是形成和雕刻行星的物理过程的重要签名。特别是，居住在半径间隙中的行星可能是这些过程的宝贵探针，因为它们可能正在经历信封损失的最后阶段。在这里，我们讨论了Fulton＆Petigura（2018; F18）和Van Eylen等人的两种半径差距的观点。 （2018; v18）。在V18中，差距更大，更不含行星。这部分归因于V18对行星半径$ r_p $的更精确的测量。多亏了Gaia，恒星Radii RSTAR中的不确定性不再是确定大多数开普勒行星的$ R_P $的限制不确定性；而是$ r_p/r_ \ star $统治中的错误。 V18的分析结合了短循环光度法，以及对平均恒星密度的约束，这使得$ r_p/r_ \ star $更准确地确定。在F18分析中，较少准确的$ r_p/r_ \ star $模糊了半径间隙的边界。 $ r_p/r_ \ star $的差异在高影响力参数（$ b \ gtrsim 0.8 $）上是最大的，通常超过10％。这激发了从人口统计学研究中排除高$ B $行星，但是仅凭长期光度测定而确定这样的行星是具有挑战性的。我们表明，过境持续时间可以作为有效的代理，我们利用这些信息来增强超级收获和亚本次群体之间的对比度。
Recently, several groups have resolved a gap that bifurcates planets between the size of Earth and Neptune into two populations. The location and depth of this feature is an important signature of the physical processes that form and sculpt planets. In particular, planets residing in the radius gap are valuable probes of these processes as they may be undergoing the final stages of envelope loss. Here, we discuss two views of the radius gap by Fulton & Petigura (2018; F18) and Van Eylen et al. (2018; V18). In V18, the gap is wider and more devoid of planets. This is due, in part, to V18's more precise measurements of planet radius $R_p$. Thanks to Gaia, uncertainties in stellar radii Rstar are no longer the limiting uncertainties in determining $R_p$ for the majority of Kepler planets; instead, errors in $R_p/R_\star$ dominate. V18's analysis incorporated short-cadence photometry along with constraints on mean stelar density that enabled more accurate determinations of $R_p/R_\star$. In the F18 analysis, less accurate $R_p/R_\star$ blurs the boundary the radius gap. The differences in $R_p/R_\star$ are largest at high impact parameter ($b \gtrsim 0.8$) and often exceed 10%. This motivates excluding high-$b$ planets from demographic studies, but identifying such planets from long-cadence photometry alone is challenging. We show that transit duration can serve as an effective proxy, and we leverage this information to enhance the contrast between the super-Earth and sub-Neptune populations.
