|Ph.D Student||Erez Michaely|
|Subject||Triple Stellar Dynamics and Evolution and Topics in|
|Department||Department of Physics||Supervisor||Professor Perets Hagai|
|Full Thesis text|
The focus of this Ph.D. thesis is exploring the origins and evolution of multiple systems (mainly triple systems), ranging in scale from satellites and planetesimals in the Solar system to triple stellar systems and X-ray binaries. Though different in scale many of these systems share similar physical processes, and can be described as Keplerian systems perturbed by additional stellar/planetary companions and/or affected by dissipative stellar evolutionary processes and tidal interactions.
In our study we explore these aspects and show the role they play in both the formation of unique systems and their evolution. In particular our research addresses several open questions and suggest novel solutions. We use analytical derivations together with secular triple evolution code developed by us which accounts for various conservative and nonconservative physical processes.
These tools were used to explore the following topics and open questions: (1) How do triple stellar systems dynamically evolve due to secular mass loss and mass transfer? The research of mass loss and mass transfer in triple stellar systems is still in its infancy. In our work we derive, analytically, the additional terms in the equation of motion of the standard triple systems due to mass loss and transfer and discuss several important channels of evolution due to this effect. (2) The hypothetical existence and properties of additional satellites of the Pluto-Charon planetary system. In this work we treat the Sun, Pluto-Charon and a moon as a triple system accounting the quadrapole moment of Pluto-Charon and its effects a hypothetical moon of the systems. Our results maps the allowed positions and eccentricities of potential far-off moons in this system.
(3) What is the origin of low-mass X-ray binaries (LMXBs) in the field? The origins of field LMXBs is a long standing problem. We consider a novel channel for LMXB formation from wide binaries in the field. We show that the impulse interaction of a wide binary in the field with fly-by stars can drive such a system to very high eccentricities to the point where tidal dissipation effects takes place. These systems circularize at the pericenter and attain a short period binary configuration in which mass-transfer occurs giving rise to the formation of a LMXB. (4) We explore in detail the dynamical aftermath of neutron stars natal kicks in binary systems, determine their possible outcomes and characterize their relative frequency. We present additional channels never discussed before, and suggest a novel type of electromagnetic precursors to gravitational-wave sources. (5) We present a numerical calculation of the dynamical interaction between the proposed Planet Nine in the Solar system and an initially thin circular debris disk around the Sun. We show that Planet Nine governs the dynamics in between 1000−5000AU and forms spherical structure in the inner part (∼ 1000AU) surrounded by an inclined disk aligned to its orbital plane.