Discovery of collimated bipolar outflows in the planetary nebula Th 2-A

TL;DR

This study uses integral field spectroscopy and 3D modeling to reveal that the planetary nebula Th 2-A features a thick toroidal shell and collimated bipolar outflows, providing insights into its complex structure and stellar characteristics.

Contribution

First detailed 3D morpho-kinematic model of Th 2-A revealing its shell and bipolar outflows based on integral field spectroscopic data.

Findings

Th 2-A has a thick toroidal shell expanding at 40 km/s.

It exhibits collimated bipolar outflows reaching 70-110 km/s.

The nebula's structure relates to its peculiar [WO]-type central star.

Abstract

We present a comprehensive set of spatially resolved, integral field spectroscopic mapping of the Wolf-Rayet planetary nebula Th 2-A, obtained using the Wide Field Spectrograph on the Australian National University 2.3-m telescope. Velocity-resolved H$\alpha$ channel maps with a resolution of 20 km s$^{-1}$ allow us to identify different kinematic components within the nebula. This information is used to develop a three-dimensional morpho-kinematic model of the nebula using the interactive kinematic modeling tool SHAPE. These results suggest that Th 2-A has a thick toroidal shell with an expansion velocity of 40 $\pm$ 10 km s$^{-1}$, and a thin prolate ellipsoid with collimated bipolar outflows toward its axis reaching velocities in the range of 70-110 km s$^{-1}$, with respect to the central star. The relationship between its morpho-kinematic structure and peculiar [WO]-type stellar characteristics deserves further investigation.