MERGERS AND OBLIQUITIES IN STELLAR TRIPLES

作者：Naoz Smadar^*; Fabrycky Daniel C

来源：Astrophysical Journal, 2014, 793(2): 137.

DOI：10.1088/0004-637X/793/2/137

• binaries: close
• binaries: general
• blue stragglers
• stars: general
• stars: kinematics and dynamics

Many close stellar binaries are accompanied by a faraway star. The "eccentric Kozai-Lidov" (EKL) mechanism can cause dramatic inclination and eccentricity fluctuations, resulting in tidal tightening of inner binaries of triple stars. We run a large set of Monte Carlo simulations, including the secular evolution of the orbits, general relativistic precession, and tides, and we determine the semimajor axis, eccentricity, inclination, and spin-orbit angle distributions of the final configurations. We find that the efficiency of forming tight binaries (less than or similar to 16 days) when taking the EKL mechanism into account is similar to 21%, and about 4% of all simulated systems ended up in a merger event. These merger events can lead to the formation of blue stragglers. Furthermore, we find that the spin-orbit angle distribution of the inner binaries carries a signature of the initial setup of the system; thus, observations can be used to disentangle close binaries' birth configuration. The resulting inner and outer final orbits' period distributions and their estimated fraction suggest that secular dynamics may be a significant channel for the formation of close binaries in triples and even blue stragglers.

• 出版日期2014-10-1