ALMA observations of the Red Rectangle, a preliminary analysis

TL;DR

This paper presents high-resolution ALMA observations of the Red Rectangle, revealing detailed structures of the equatorial disk and outflows in a post-AGB object, advancing understanding of planetary nebula formation.

Contribution

It provides the first simultaneous observation of both disk and outflow in the Red Rectangle, offering new insights into their structure and dynamics.

Findings

Confirmed properties of the rotating disk

Identified a low-velocity outflow between the disk and nebula

Provided initial physical conditions of the outflow

Abstract

We aim to study equatorial disks in rotation and axial outflows in post-AGB objects, as to disclose the formation and shaping mechanisms in planetary nebulae. So far, both disks and outflows had not been observed simultaneously. We have obtained high-quality ALMA observations of 12CO and 13CO J=3-2 and 12CO J=6-5 line emission in the Red Rectangle, the only post-AGB/protoplanetary object in which a disk in rotation has been mapped up to date. These observations provide an unprecedented description of the complex structure of this source. Together with an equatorial disk in rotation, we find a low-velocity outflow that occupies more or less the region placed between the disk and the optical X-shaped nebula. From our observations and preliminary modeling of the data, we confirm the previously known properties of the disk and obtain a first description of the structure, dynamics, and physical conditions of the outflow.