Kinematical Investigation of Possible Fast Collimated Outflows in Twelve Planetary Nebulae

TL;DR

This study investigates the presence and characteristics of collimated outflows in twelve planetary nebulae using spectroscopic and imaging data, revealing diverse outflow behaviors and their possible relation to nebula age and progenitor mass.

Contribution

It provides the first detailed spatio-kinematical analysis of collimated outflows in a sample of twelve planetary nebulae, confirming their presence and exploring their interaction with nebular envelopes.

Findings

Collimated outflows confirmed in six PNe.

Some PNe show outflows that haven't pierced the nebular envelope.

Outflows are more common in older or higher-mass progenitor PNe.

Abstract

A significant fraction of planetary nebulae (PNe) exhibit collimated outflows, distinct narrow kinematical components with notable velocity shifts with respect to the main nebular shells typically associated with low-ionization compact knots and linear or precessing jet-like features. We present here a spatio-kinematical investigation of a sample of twelve PNe with morphologies in emission lines of low-ionization species suggestive of collimated outflows. Using archival narrow-band images and our own high-dispersion long-slit echelle spectra, we confirm the presence of collimated outflows in Hen 2-429, J 320, M 1-66, M 2-40, M 3-1, and NGC 6210 and possibly in NGC 6741, for which the spatio-kinematical data can also be interpreted as a pair of bipolar lobes. The presence of collimated outflows is rejected in Hen 2-47, Hen 2-115, M 1-26, and M 1-37, but their morphology and kinematics are indicative of the action of supersonic outflows that have not been able to pierce through the nebular envelope. In this sense, M 1-66 appears to have experienced a similar interaction between the outflow and nebular envelope, but, as opposed to these four PNe, the outflow has been able to break through the nebular envelope. It is suggested that the PNe without collimated outflows in our sample are younger or descend from lower mass progenitors than those that exhibit unambiguous collimated outflows.