Hot Jupiters from Coplanar High-eccentricity Migration

摘要: We study the possibility that hot Jupiters are formed through secular gravitational interactions between two planets in eccentric orbits with relatively low mutual inclinations ($\lesssim20^\circ$) and friction due to tides raised on planet by host star. term this migration mechanism Coplanar High-eccentricity Migration because, like disk migration, it allows for occur same plane which formed. can operate from following typical initial configurations: (i) inner a circular orbit outer an eccentricity $\gtrsim0.67$ $m_{\rm in}/m_{\rm out}(a_{\rm in}/a_{\rm out})^{1/2}\lesssim0.3$; (ii) ($\gtrsim0.5$) out})^{1/2}\lesssim0.16$. A population synthesis of hierarchical systems giant using observed distribution shows produces stellar obliquities ($\lesssim30^\circ$), semi-major axis matches observations, at rate account their occurrence. different is needed create large obliquity Jupiters, either channel or tilts star proto-planetary disk. predicts should have distant ($a\gtrsim5$ AU) massive (most likely $\sim1-3$ more than Jupiter) companions ($\lesssim 20^\circ$) moderately high eccentricities ($e\sim0.2-0.5$)