We present Submillimeter Array (SMA) mapping of 12CO J=2→1, 13CO J=2→1, and CN N=2→1 emission from the Ring-like planetary nebula (PN) NGC 3132, one of the subjects of JWST Early Release Observation (ERO) near-infrared imaging. The ∼5′′ resolution SMA data demonstrate that the Southern Ring's main, bright, molecule-rich ring is indeed an expanding ring, as opposed to a limb-brightened shell, in terms of its intrinsic (physical) structure. This suggests that NGC 3132 is a bipolar nebula viewed more or less pole-on (inclination ∼15--30∘). The SMA data furthermore reveal that the nebula harbors a second expanding molecular ring that is aligned almost orthogonally to the main, bright molecular ring. We propose that this two-ring structure is the remnant of an ellipsoidal molecular envelope of ejecta that terminated the progenitor star's asymptotic giant branch evolution and was subsequently disrupted by a series of misaligned fast, collimated outflows or jets resulting from interactions between the progenitor and one or more companions.
@article{arxiv.2402.11850,
title = {The Molecular Exoskeleton of the Ring-like Planetary Nebula NGC 3132},
author = {Joel H. Kastner and David Wilner and Paula Moraga Baez and Jesse Bublitz and Orsola De Marco and Raghvendra Sahai and Al Wootten},
journal= {arXiv preprint arXiv:2402.11850},
year = {2024}
}
Comments
20 pages, 12 figures; accepted by The Astrophysical Journal