AI 中文总结
研究多行星系统中行星质量-半径关系与动力学结构的关联，通过分离特定行星比较性质，发现经历撞击的行星平均质量更大，氢包层质量分数不小，表明动力学演化和碰撞是行星系统演化一部分且须尽早发生。
AI 中文摘要
我们研究了多行星系统中行星的质量-半径关系与其动力学结构的函数关系。我们分离出那些接近共振表明自形成以来未经历重大动力学不稳定、因此未与另一颗行星发生晚期巨大撞击的行星。我们将这些行星的性质与那些轨道结构表明极有可能经历过巨大撞击的行星的性质进行比较。我们发现，可能经历过撞击的行星平均比未经历过撞击的行星质量更大，这与先前的说法一致。然而，我们发现这些行星的氢包层质量分数不小于未经历碰撞的行星。这些发现共同表明，动力学演化和行星碰撞是致密行星系统演化的一个组成部分，但它们必须足够早地发生，以使碰撞残余物仍能从消散的原行星盘中重新捕获气态包层。
英文摘要
We study the mass-radius relationship of planets in multiplanet systems as a function of their dynamical architecture. We isolate those planets whose proximity to resonance indicates that they have not undergone significant dynamical instability since formation, and therefore have not experienced a late giant impact with another planet. We compare the properties of these planets to those whose orbital architectures suggest a high probability of having experienced a giant impact. We find that planets that are likely to have experienced an impact are, on average, more massive than those that did not -- consistent with prior claims. However, we find that the Hydrogen envelope mass fractions of these planets are no smaller than those of planets that did not experience collisions. Taken together, these findings suggest that dynamical evolution and planetary collisions are an integral part of the evolution of compact planetary systems, but that they must occur early enough that collisional remnants are still able to recapture gaseous envelopes from the dissipating protoplanetary disk.
Comments14 pages, 12 figures, submitted to Open Journal of Astronomy
