An asymmetric jet launching model for the protoplanetary nebula CRL 618

TL;DR

This paper introduces an asymmetric jet ejection model using 3D hydrodynamical simulations to explain the mirror symmetry and morphology of the protoplanetary nebula CRL 618, aligning well with observations.

Contribution

It presents a novel asymmetric jet launching mechanism involving a precessing jet from an orbiting source, explaining observed nebula features.

Findings

Reproduces mirror symmetry in nebula lobes

Matches observed lobe sizes and distribution

Kinematic ages align with observations

Abstract

We propose an asymmetrical jet ejection mechanism in order to model the mirror symmetry observed in the lobe distribution of some protoplanetary nebulae (pPNe), such as the pPN CRL 618. 3D hydrodynamical simulations of a precessing jet launched from an orbiting source were carried out including an alternation in the ejections of the two outflow lobes, depending on which side of the precessing accretion disk is hit by the accretion column from a Roche lobe-filling binary companion. Both synthetic optical emission maps and position-velocity (PV) diagrams were obtained from the numerical results with the purpose of carrying out a direct comparison with observations. Depending on the observer's point of view, multipolar morphologies are obtained which exhibit a mirror symmetry at large distances from the central source. The obtained lobe sizes and their spatial distribution are in good agreement with the observed morphology of the pPN CRL 618. We also obtain that the kinematic ages of the fingers are similar to those obtained in the observations.