The kinematics and binary-induced shaping of PN HaTr 4

TL;DR

This study provides the first detailed 3D kinematic model of planetary nebula HaTr 4, demonstrating how its binary central star influences its morphology, confirming a direct link between binarity and nebular shaping.

Contribution

It offers the first detailed spatio-kinematical analysis of HaTr 4, revealing the influence of its binary central star on its morphology and orientation.

Findings

HaTr 4 has an extended ovoid shape with a toroidal waist.

The nebula's inclination matches the binary plane, indicating binary influence.

HaTr 4 is one of only five PNe with confirmed binary-shaping evidence.

Abstract

We present the first detailed spatio-kinematical analysis of the planetary nebula HaTr 4, one of few known to contain a post-Common-Envelope central star system. Based on high spatial and spectral resolution spectroscopy of the [OIII]5004.84 angstrom nebular emission line, in combination with deep, narrow-band imagery, a spatio-kinematical model was developed in order to accurately determine the three-dimensional morphology and orientation of HaTr 4. The nebula is found to display an extended ovoid morphology with an equatorial enhancement consistent with a toroidal waist - a feature believed to be typical of central star binarity. The nebular inclination is found to be in good agreement with that determined for the binary plane, providing strong evidence that shaping and evolution of HaTr 4 has been influenced by its central binary system - making HaTr 4 one of only 5 planetary nebulae to have had this observationally proven.