Deep study of the fast bipolar outflows in pre-PNe from CO mm-wave line emission

TL;DR

This study investigates the physical properties of bipolar outflows in pre-planetary nebulae using high-resolution CO line emission data, aiming to understand the transition from spherical AGB envelopes to axisymmetric nebulae.

Contribution

It introduces a detailed emission model for molecular gas in pre-PNe, enabling separate analysis of bipolar and spherical components to elucidate nebular shaping processes.

Findings

Determined physical parameters of bipolar and spherical nebular components.

Analyzed individual sources to understand morphological evolution.

Placed results within an evolutionary framework.

Abstract

High spatial resolution images of PNe have shown their extremely complex morphology. However, the circumstellar envelopes of their progenitors, the AGB stars, are strikingly spherical. In order to understand the carving processes leading to axisymmetric nebulae, we are carrying out a study of a large sample of pre-PNe. Our emission model of the nebular molecular gas (12CO & 13CO) will allow us to determine important physical parameters (mass, linear momentum, kinetic energy) of the fast bipolar and slow spherical nebular components separately. We will study in an innovative way the properties for each source individually, and put our results in an evolutionary context with the help of the data obtained by us and collected from the literature.