The influence of binarity on the morpho-kinematics of planetary nebulae

TL;DR

This study uses spatio-kinematical modeling of planetary nebulae with close binary central stars to test the hypothesis that binarity influences nebular shaping, supporting the idea that binary interactions are crucial in nebula formation.

Contribution

It provides observational evidence linking binary central stars to nebular morphology through detailed modeling, confirming theoretical predictions about nebular alignment.

Findings

All modeled nebulae show the predicted perpendicular alignment.

Binary central stars influence the shaping of planetary nebulae.

Supports the hypothesis that binarity is key in nebula evolution.

Abstract

The role of central star binarity in the shaping of planetary nebulae (PNe) has been the subject of much debate, with single stars believed to be incapable of producing the most highly collimated morphologies. However, observational support for binary-induced shaping has been sadly lacking. Here, we highlight the results of a continuing programme to spatio-kinematically model the morphologies of all PNe known to contain a close binary central star. Spatio-kinematical modelling is imperative for these objects, as it circumvents the degeneracy between morphology and orientation which can adversely affect determinations of morphology based on imaging alone. Furthermore, spatio-kinematical modelling accurately determines the orientation of the nebular shell, allowing the theoretically predicted perpendicular alignment, between nebular symmetry axis and binary orbital plane, to be tested. To date, every PN subjected to this investigation has displayed the predicted alignment, indicating that binarity has played an important role in the formation and evolution of these nebulae. The further results from this programme will be key, not only in determining whether binary interaction is responsible for shaping the studied PNe, but also in assessing the importance of binarity in the formation and evolution of all PNe in general.