论文标题
行星迁移的过渡变化签名：K2-24的情况
Transit-Timing Variation Signature of Planet Migration: The Case of K2-24
论文作者
论文摘要
气盘中两个行星的收敛迁移可以导致平均运动共振（MMR）捕获。另外，已知MMR中或附近的一对行星对产生强大的传输时间变化（TTV）。在本文中，我们研究了圆盘诱导的迁移对进入谐振构型的行星对TTV信号的影响。我们表明，椎间盘诱导的迁移在幅度与TTV的周期之间建立了相关性。我们研究了K2-24的案例，K2-24是两个行星的系统，其周期比表明它们在2：1 MMR中，具有非零偏心率和大振幅TTV。我们表明，简单的椎间盘引起的迁移无法再现观察到的TTV，我们提出了一种形成场景，在这种情况下，在具有强烈偏心衰减的光盘中迁移期间发生共鸣的捕获在盘子分散过程中的偏心性激发后，在第三个行星的辅助过程中得到了散热性观察的辅助。这种情况解释了两个行星的偏心率及其周期比，并准确地再现了TTV的幅度和周期。它允许从椎间盘诱导的迁移到当前观察到的特性的K2-24的形成和进化历史的统一视图。
The convergent migration of two planets in a gaseous disc can lead to capture in mean motion resonance (MMR). In addition, pairs of planets in or near MMRs are known to produce strong transit timing variations (TTVs). In this paper we study the impact of disc-induced migrations on the TTV signal of pairs of planets that enter a resonant configuration. We show that disc-induced migration creates a correlation between the amplitude and the period of the TTVs. We study the case of K2-24, a system of two planets whose period ratio indicates that they are in or near the 2:1 MMR, with non-zero eccentricities and large-amplitude TTVs. We show that a simple disc-induced migration cannot reproduce the observed TTVs, and we propose a formation scenario in which the capture in resonance occurring during migration in a disc with strong eccentricity damping is followed by eccentricity excitation during the dispersal of the disc, assisted by a third planet whose presence has been suggested by radial velocity observations. This scenario accounts for the eccentricities of the two planets and their period ratio, and accurately reproduces the amplitude and period of the TTVs. It allows for a unified view of the formation and evolution history of K2-24, from disc-induced migration to its currently observed properties.
