发表机构
California Institute of Technology; Indiana University; Yale University; University of California, Los Angeles; University of California, Santa Barbara; NASA Exoplanet Science Institute, Caltech/IPAC（加州理工学院; 印第安纳大学; 耶鲁大学; 加利福尼亚大学洛杉矶分校; 加利福尼亚大学圣塔芭芭拉分校; NASA系外行星科学研究所，Caltech/IPAC）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过同质普查发现恒星伴星显著增强热木星形成与自转-轨道错位，伴星比例约为场星3-4倍，且错位率随温度升高而上升，支持高偏心迁移机制。
AI 中文摘要
恒星伴星可以驱动热木星（HJ）的迁移和自转-轨道错位，但它们在热木星形成中的作用仍不确定。我们构建了一个对147颗具有测量投影倾斜率的北方热木星的已分辨恒星伴星的同质普查。我们获得了均匀的自适应光学成像，并将这些观测与{\it Gaia}共同自行对相结合，识别出8个新的伴星候选体，使\textit{观测到的}伴星比例达到$71/147=48\\%$。对完整巡天选择函数进行建模，得出质量比$q_\star=0.1$-$1$、投影间距$s=50$-$50{,}000$~au的\textit{固有}伴星比例为$62\pm5\\%$，大约是场星的3-4倍。包括白矮星伴星将进一步增加这一比例。在$50$-$2{,}000$~au处具有已分辨伴星的热木星，其错位可能性几乎是未探测到伴星系统的两倍：$46\\%$对比$24\\%$（$p=0.009$）。错位比例从最冷宿主中的$5\\%$稳步上升到最热宿主中的$80\\%$，在Kraft断裂处没有急剧转变，而固有伴星比例在温度范围内大致保持恒定。这些趋势与热木星开始时具有广泛的倾斜率分布，随后在较高恒星温度下潮汐重排逐渐减弱相一致。与之前的工作相反，我们发现样本中的大多数恒星伴星在合适的轨道构型下能够驱动偏心Kozai-Lidov（EKL）振荡到达潮汐极限，使得高偏心迁移在动力学上具有前景。综合来看，这些结果表明恒星伴星塑造了热木星的形成和自转-轨道结构。
英文摘要
Stellar companions can drive hot-Jupiter (HJ) migration and spin-orbit misalignment, but their role in HJ formation remains uncertain. We construct a homogeneous census of resolved stellar companions to $147$ northern HJs with measured projected obliquities. We obtain uniform adaptive-optics imaging and combine these observations with {\it Gaia} common proper-motion pairs to identify 8 new companion candidates, bringing the \textit{observed} companion fraction to $71/147=48\%$. Modeling the full survey selection function yields an \textit{intrinsic} companion fraction of $62\pm5\%$ for mass ratios $q_\star=0.1$-$1$ and projected separations $s=50$-$50{,}000$~au, roughly 3-4$\times$ enhanced relative to field stars. Including white-dwarf companions would increase this fraction further. HJs with resolved companions at $50$-$2{,}000$~au are nearly twice as likely to be misaligned compared to systems without detected companions: $46\%$ compared to $24\%$ ($p=0.009$). The misaligned fraction rises steadily from $5\%$ among the coolest hosts to $80\%$ among the hottest, without a sharp transition at the Kraft Break, while the intrinsic companion fraction remains roughly constant across the temperature range. These trends are consistent with HJs beginning with a broad obliquity distribution, followed by progressively weaker tidal realignment at higher stellar temperatures. Contrary to previous work, we find that most stellar companions in our sample are capable of driving eccentric Kozai-Lidov (EKL) oscillations to the tidal limit under suitable orbital configurations, making high-eccentricity migration dynamically promising. Taken together, these results indicate that stellar companions sculpt HJ formation and spin--orbit architectures.
Comments46 pages, 22 figures, 5 tables, including appendices. Submitted to PASP. Comments welcome
