Astron. Astrophys. Suppl. Ser. 138, 299-322

Oxygen-rich semiregular and irregular variables

A catalogue of circumstellar CO observations

F. Kerschbaum¹² - H. Olofsson²

Send offprint request: F. Kerschbaum,
Internet: kerschbaum@astro.univie.ac.at

1 - Institut für Astronomie, Türkenschanzstraße 17, A-1180 Wien, Austria
2 - Stockholms Observatorium, SE-13336 Saltsjöbaden, Sweden

Received February 25; accepted June 4, 1999

Abstract:

Using the SEST, the Onsala 20m telescope, the JCMT, and the IRAM 30m telescope we have carried out a survey of circumstellar CO(J=1-0, 2-1, 3-2, and 4-3) emission on a large sample of oxygen-rich semiregular (SRa and SRb) and irregular variables (Lb). A total of 109 stars were observed in at least one CO line: 66 were shown to have circumstellar CO line emission (7 SRa, 36 SRb, and 23 Lb variables), $\sim$ 60% of the semiregulars and all but one of the irregulars were detected for the first time. Most stars were observed in at least two transitions. There is a total of 138 detected CO lines. For twelve stars strong interference from interstellar CO emission precluded detection.

We present here a catalogue of all observational data and the spectra of all detections, as well as brief discussions on detection statistics (including its dependence on variability type, period, IRAS-colour, IRAS LRS-class, and M-subclass), line profiles (including line shape asymmetry, multi-component line shapes, and line intensity ratios), gas expansion velocity distributions, and correlations between CO line and IR continuum fluxes (including implications for the mass-loss mechanism).

Key words: stars: variables: general -- stars: AGB and post-AGB -- stars: circumstellar matter -- stars: mass-loss -- radio lines: stars