ALMA observations of the vibrationally excited rotational CO transition v = 1, J = 3 - 2 towards five AGB stars
Journal article, 2016

We report the serendipitous detection with the Atacama Large Millimeter/submillimeter Array (ALMA) of the vibrationally excited pure-rotational CO transition v = 1, J = 3 - 2 towards five asymptotic giant branch (AGB) stars, o Cet, R Aqr, R Scl, W Aql, and ?1 Gru. The observed lines are formed in the poorly understood region located between the stellar surface and the region where the wind starts, the so-called warm molecular layer. We successfully reproduce the observed lines profiles using a simple model. We constrain the extents, densities, and kinematics of the region where the lines are produced. R Aqr and R Scl show inverse P-Cygni line profiles which indicate infall of material on to the stars. The line profiles of o Cet and R Scl show variability. The serendipitous detection towards these five sources shows that vibrationally excited rotational lines can be observed towards a large number of nearby AGB stars using ALMA. This opens a new possibility for the study of the innermost regions of AGB circumstellar envelopes. © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Circumstellar mattercover-date

Line: profiles

Stars: AGB and post-AGB

Author

Theo Khouri

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Wouter Vlemmings

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

S. Ramstedt

Uppsala University

Robin Lombaert

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Matthias Maercker

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Elvire De Beck

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Monthly Notices of the Royal Astronomical Society: Letters

17453925 (ISSN) 17453933 (eISSN)

Vol. 463 1 L74-L78

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

Infrastructure

Onsala Space Observatory

DOI

10.1093/mnrasl/slw161

More information

Latest update

2/28/2018