Discovery of Collimated Bipolar Outflows in the Planetary Nebula TH 2-A

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 Hα 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 ± 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.