Astron. Astrophys. Suppl. Ser.
Volume 138, Number 2, August 1999
|Page(s)||299 - 322|
|Published online||15 August 1999|
Oxygen-rich semiregular and irregular variables*
A catalogue of circumstellar CO observations
Institut für Astronomie, Türkenschanzstraße 17, A-1180 Wien, Austria
2 Stockholms Observatorium, SE-13336 Saltsjöbaden, Sweden
Send offprint request to: F. Kerschbaum,
Accepted: 4 June 1999
Using the SEST, the Onsala 20 m telescope, the JCMT, and the IRAM 30 m telescope we have carried out a survey of circumstellar CO(, 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), ~ 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-compo nent 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
© European Southern Observatory (ESO), 1999