约束热木星族群中的潮汐迁移
Constraining Tidal Migration with the Hot Jupiter Population
- Princeton University（普林斯顿大学）
- University of California, Santa Barbara（加州大学圣塔芭芭拉分校）
- Canadian Institute for Theoretical Astrophysics（加拿大理论天体物理研究所）
- University of California Los Angeles（加州大学洛杉矶分校）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文通过分析热木星周期分布，提出一个约束潮汐迁移的框架，发现χτ≈3的模型与观测最吻合，暗示新圆化热木星周期集中在3-4天。
AI中文摘要：
轨道周期短于几天的热木星可能受到了潮汐轨道迁移的影响。我们开发了一个分析框架，用于根据当今热木星周期分布来约束潮汐迁移，同时考虑了由高偏心迁移或盘驱动迁移等机制产生的热木星的不确定速率和周期分布。假设潮汐迁移时间尺度与 $P^{\chi_\tau}$ 成正比，则 $\chi_\tau \simeq 3, 1.7,$ 和 $5.6$ 的解都与当今的周期分布兼容。$\chi_\tau \simeq 3$ 的解与平衡潮在短周期处耗散受到抑制的模型一致，并暗示新近圆化的热木星周期集中在 $3-4$ 天附近，正如某些高偏心迁移模型所预测的那样。$\chi_\tau \simeq 1.7$ 的解也与 $3-4$ 天的峰值兼容，但在现有潮汐理论中没有明确对应，且需要更精细的调谐。$\chi_\tau \simeq 5.6$ 的解与短周期平衡潮耗散增强或弱非线性重力波耗散兼容，但要求在出乎意料的短周期处发生圆化。因此，我们认为 $\chi_\tau \simeq 3$ 的模型最具吸引力。对单个系统的凌日计时观测以及对热木星吞噬速率的观测约束提供了额外限制，目前这些约束尚无定论，但未来数据应能改善。改进对短周期行星发生率随行星质量和系统年龄变化的测量，也有助于加强潮汐迁移的约束。
英文摘要：
Hot Jupiters with orbital periods shorter than a few days have probably been affected by tidal orbital migration. We develop an analytical framework for constraining tidal migration from the present-day hot Jupiter period distribution, taking into account the uncertain rate and period distribution of hot Jupiters produced by mechanisms such as high-eccentricity migration or disk-driven migration. Assuming the tidal migration timescale is proportional to $P^{χ_τ}$, solutions with $χ_τ\simeq 3, 1.7,$ and 5.6 are all compatible with the present-day period distribution. The $χ_τ\simeq 3$ solution is consistent with equilibrium tides with suppression of dissipation at short periods, and implies that newly circularized hot Jupiters have periods concentrated near $3-4$ days, as predicted in some high-eccentricity migration models. The $χ_τ\simeq 1.7$ solution is also compatible with the $3-4$ day peak but has no clear counterpart in existing tidal theories and is more finely tuned. The $χ_τ\simeq 5.6$ solution is compatible with enhanced short-period equilibrium tidal dissipation or weakly nonlinear gravity-wave dissipation, but requires circularization at unexpectedly short periods. Thus, we find the model with $χ_τ\simeq 3$ most appealing. Transit timing of individual systems and observational constraints on the rate of hot Jupiter engulfment provide additional constraints, which are presently inconclusive but should improve with future data. Improved measurements of the occurrence of short-period planets as a function of planet mass and system age could also help to sharpen the constraints on tidal migration.
