Neutron Star-Main Sequence Collisions Robustly Form Dynamically Stable Thorne-\.Zytkow Objects

Abstract

Thorne-\.Zytkow Objects (T\.ZOs) are hypothetical hybrid stars with a neutron star at the core of a large, diffuse envelope. (T\.ZOs) may be formed when a newly formed neutron star that is kicked by its supernova collides with its main-sequence companion. Using a moving-mesh hydrodynamics solver integrated into the parallel-code Charm N-body GrAvity solver, we demonstrate that these ``impact scenario'' formation processes robustly form (T\.ZOs) for periastron distances less than one stellar radius. These (T\.ZOs) are dynamically stable and they can serve as initial models for further evolutionary studies.