Morphologies of Wolf-Rayet Planetary Nebulae based on IFU Observations

Abstract

Integral field unit (IFU) spectroscopy of planetary nebulae (PNe) provides a plethora of information about their morphologies and ionization structures. An IFU survey of a sample of PNe around hydrogen-deficient stars has been conducted with the Wide Field Spectrograph (WiFeS) on the ANU 2.3-m telescope. In this paper, we present the H$\alpha$ kinematic observations of the PN M2-42 with a weak emission-line star ($wels$), and the compact PNe Hen 3-1333 and Hen 2-113 around Wolf-Rayet ([WR]) stars from this WiFeS survey. We see that the ring and point-symmetric knots previously identified in the velocity [N II] channels of M2-42 are also surrounded by a thin exterior ionized H$\alpha$ halo, whose polar expansion is apparently faster than the low-ionization knots. The velocity-resolved H$\alpha$ channel maps of Hen3-1333 and Hen2-113 also suggest that the faint multipolar lobes may get to a projected outflow velocity of $\sim 100 \pm 20$ km s$^{-1}$ far from the central stars. Our recent kinematic studies of the WiFeS/IFU survey of other PNe around [WR] and $wels$ mostly hint at elliptical morphologies, while collimated outflows are present in many of them. As the WiFeS does not have adequate resolution for compact ($\leq 6$ arcsec) PNe, future high-resolution spatially-resolved observations are necessary to unveil full details of their morpho-kinematic structures.