Opening PANDORA's box: APEX observations of CO in PNe

Abstract

Context. Observations of molecular gas have played a key role in developing the current understanding of the late stages of stellar evolution. Aims. The survey Planetary nebulae AND their cO Reservoir with APEX (PANDORA) was designed to study the circumstellar shells of evolved stars with the aim to estimate their physical parameters. Methods. Millimetre carbon monoxide (CO) emission is the most useful probe of the warm molecular component ejected by low- to intermediate-mass stars. CO is the second-most abundant molecule in the Universe, and the millimeter transitions are easily excited, thus making it particularly useful to study the mass, structure, and kinematics of the molecular gas. We present a large survey of the CO (J = 3 - 2) line using the Atacama Pathfinder EXperiment (APEX) telescope in a sample of 93 proto-planetary nebulae and planetary nebulae. Results. CO (J = 3 - 2) was detected in 21 of the 93 objects. Conclusions. CO (J = 3 - 2) was detected in all 4 observed pPNe (100%), 15 of the 75 PNe (20%), one of the 4 wide binaries (25%), and in 1 of the 10 close binaries (10%). Using the CO (J = 3 - 2) line, we estimated the column density and mass of each source.

arXiv comment24 pages, accepted for publication in the A&A Journal

References in corpus (27)

• The Milky Way in Molecular Clouds: A New Complete CO Survey
• A computer program for fast non-LTE analysis of interstellar line spectra
• Astrophysics Source Code Library
• Automated data reduction workflows for astronomy
• Astrophysical supplements to the ASCC-2.5. Ia. Radial velocities of about 55000 stars and mean radial velocities of 516 Galactic open clusters and associations
• A Hubble Space Telescope Survey for Resolved Companions of Planetary-Nebula Nuclei
• Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System
• Fuel Efficient Galaxies: Sustaining Star Formation with Stellar Mass Loss
• Multiple Molecular Winds in Evolved Stars I. A Survey of CO(2-1) and CO(3-2) Emission from 45 Nearby AGB Stars
• Binary stars as the key to understanding planetary nebulae
• Opacity broadening and interpretation of suprathermal CO linewidths: Macroscopic Turbulence and Tangled Molecular Clouds
• ALFA: an automated line fitting algorithm
• Discovery of close binary central stars in the planetary nebulae NGC 6326 and NGC 6778
• The post-common envelope central stars of the planetary nebulae Henize 2-155 and Henize 2-161
• An independent distance estimate to CW Leo
• A CO Survey of Young Planetary Nebulae
• SALT reveals the barium central star of the planetary nebula Hen 2-39
• The morphology and kinematics of the Fine Ring Nebula, planetary nebula Sp 1, and the shaping influence of its binary central star
• Multiple Molecular H2 Outflows in AFGL 618
• ALMA view of the circumstellar environment of the post-common-envelope-evolution binary system HD101584
• High Resolution Millimeter Imaging of the Proto-Planetary Nebula He 3-1475
• Two short mass-loss events that unveil the binary heart of Minkowski's Butterfly Nebula
• Hen 2-104: A close-up look at the Southern Crab
• HI and CO Observations of Circumnebular Envelopes of Planetary Nebulae
• First detection of methanol towards a post-AGB object, HD101584
• A molecular line survey of a sample of AGB stars and planetary nebulae
• An Envelope Disrupted by a Quadrupolar Outflow in the Pre-Planetary Nebula IRAS19475+3119

Cited by in corpus (5)

• Planetary Nebulae: Sources of Enlightenment
• The MUSE view of the planetary nebula NGC 3132
• The ionised and molecular mass of post-common-envelope planetary nebulae. The missing mass problem
• A search for cool molecular gas in GK Persei and other classical novae
• Discovery of Raman-scattered He II $\lambda$6545 in the Planetary Nebulae NGC 6886 and NGC 6881