3D hydrodynamical models of point-symmetric planetary nebulae: the special case of H1-67

TL;DR

This paper uses 3D hydrodynamical simulations to model the point-symmetric morphology of planetary nebula H1-67, demonstrating how precessing jets with variable ejection parameters can reproduce observed features.

Contribution

It introduces detailed 3D hydrodynamical models of precessing jets with time-dependent ejection properties to explain nebular morphology, specifically applied to H1-67.

Findings

Precessing jets with >30° cone angle reproduce point-symmetric structures.

Synthetic PV diagrams match observed high-velocity jets in H1-67.

Models suggest jet precession causes S-shaped nebular morphologies.

Abstract

We present 3D hydrodynamical simulations of a precessing jet with a time-dependent ejection velocity or a time-dependent ejection density, interacting with a circumstellar medium given by a dense, anisotropic, and slow AGB wind, forming a torus. We explore a set of configurations with different values for the precession angle and number of ejections. The temporal evolution of these models is analised at times up to 1500 or 1800 yr. From our hydrodynamical models, we obtain position-velocity diagrams (PV diagrams) in the [NII]{\lambda}6583 line to be compared with high resolution observations of the planetary nebula H1-67. From spectral data this object shows high-velocity jets and a point-symmetric morphology. With our synthetic PV diagrams we show that a precessing jet with a time-dependent ejection velocity or a time-dependent ejection density reproduce the point-symmetric morphological structure for this nebula if the precession cone angle is larger than 30$^{\circ}$. Our synthetic PV diagrams can be used to understand how the S-like morphology, also presented by other planetary nebulae, is formed. For H1-67 we found a heliocentric velocity of -8.05 km s^-1 and height below the galactic plane of -451.6 pc.