Image Details
Caption: Figure 6.
Schematic plot of binary disruption and the subsequent evolution of the captured star. A binary is disrupted by the central SMBH when the binary approaches rt,b, with one of the two stars being ejected and the other being captured. In rp−a phase space, the captured star is deposited at the green dashed line, where the two ⋆ symbols denote the upper and the lower limits [Equation (36)], respectively. Depending on the initial separation of the binary, the captured star faces two possible fates: rpTDE or stellar EMRI. In the upper panel (for M• = 106 M⊙), the captured stars are in the two-body-scattering-dominated regime [Equation (34)], where those with aGW < a < a10yr finally end as observable rpTDEs. In the lower panel (M• = 107 M⊙), the captured stars with Tobt < 10 yr are in the GW-emission-dominated regime (a10yr < aGW), where those with rp ≈ 2rt start the rpTDE phase immediately after the binary disruption, while others gradually circularize and end as stellar EMRIs.
© 2026. The Author(s). Published by the American Astronomical Society.