Asymmetric supernova in hierarchical multiple star systems and application to J1903+0327

TL;DR

This paper introduces a new analytical method to evaluate the impact of asymmetric supernovae on complex hierarchical star systems, extending previous binary-focused studies to triples and higher multiplicity systems.

Contribution

The authors develop a recursive analytical approach to analyze supernova effects on hierarchical multiple star systems, including orbital changes and runaway velocities, applied to the progenitor of PSR J1903+0327.

Findings

Hierarchical triple systems can become unstable after a supernova, leading to ejection of a star.

The most probable post-supernova configuration involves small kick velocities and specific mass transfer fractions.

The method confirms the evolution scenario for PSR J1903+0327 involving a hierarchical triple disruption.

Abstract

We develop a method to analyze the effect of an asymmetric supernova on hierarchical multiple star systems and we present analytical formulas to calculate orbital parameters for surviving binaries or hierarchical triples and runaway velocities for their dissociating equivalents. The effect of an asymmetric supernova on the orbital parameters of a binary system has been studied to great extent (e.g. Hills 1983; Kalogera 1996; Tauris & Takens 1998), but this effect on higher multiplicity hierarchical systems has not been explored before. With our method, the supernova effect can be computed by reducing the hierarchical multiple to an effective binary by means of recursively replacing the inner binary by an effective star at the center of mass of that binary. We apply our method to a hierarchical triple system similar to the progenitor of PSR J1903+0327 suggested by Portegies Zwart et al. (2011). We confirm their earlier finding that PSR J1903+0327 could have evolved from a hierarchical triple that became unstable and ejected the secondary star of the inner binary. Furthermore, if such as system did evolve via this mechanism the most probable configuration would be a small supernova kick velocity, an inner binary with a large semi-major axis, and the fraction of mass accreted onto the neutron star to the mass lost by the secondary would most likely be between 0.35 and 0.5