Carbon monoxide emission from planetary nebulae and their possible precursors

Journal Article · Mon Aug 15 04:00:00 EDT 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/161228· OSTI ID:5471475

Thronson, Jr, H A; Mozurkewich, D

Carbon monoxide emission has been searched for in four planetary nebulae and four possible protoplanetary nebulae. No /sup 12/CO emission was seen in the planetary nebulae, nor in M1--92, to a level of T(/sub A/approx.20 mK. Improved /sup 12/CO spectra are discussed for AFGL 618, AFGL 2688, and CIT 6. All three objects were also detected in /sup 13/CO emission. This allowed lower limits to the (/sup 12/C)/(/sup 13/C) abundance ratio to be calculated. Our observations place upper limits to the /sup 12/CO emission from the planetary nebulae nearly two orders of magnitude below the level found in NGC 7027. We argue that a higher mass-loss rate in NGC 7027 is responsible for its detectable molecular cloud.

• Research Organization: Wyoming Infrared Observatory, University of Wyoming
• OSTI ID: 5471475
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 267:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CARBON 12
CARBON 13
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
EMISSION
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
NEBULAE
NUCLEI
OXIDES
OXYGEN COMPOUNDS
PLANETARY NEBULAE
SPECTRA
STABLE ISOTOPES