The Molecular Exoskeleton of the Ring-like Planetary Nebula NGC 3132

• Published in: The Astrophysical journal Vol. 965; no. 1; pp. 21 - 35
• Main Authors: Kastner, Joel H., Wilner, David J., Moraga Baez, Paula, Bublitz, Jesse, De Marco, Orsola, Sahai, Raghvendra, Wootten, Al
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.04.2024; IOP Publishing
• Subjects: Ejecta; Exoskeletons; Infrared imaging; Molecular gas; Planetary nebulae; Radio interferometry; Ring structures; Stellar winds
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ad2848

We present Submillimeter Array (SMA) mapping of 12 CO J = 2 → 1, 13 CO J = 2 → 1, and CN N = 2 → 1 emission from the ring-like planetary nebula NGC 3132, one of the subjects of JWST Early Release Observation 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.