ALMA spectrum of the extreme OH/IR star OH 26.5+0.6
Abstract
We present ALMA band 7 data of the extreme OH/IR star, OH 26.5+0.6. In addition to lines of CO and its isotopologues, the circumstellar envelope also exhibits a number of emission lines due to metal-containing molecules, e.g., NaCl and KCl. A lack of C18O is expected, but a non-detection of C17O is puzzling given the strengths of H217O in Herschel spectra of the star. However, a line associated with Si17O is detected. We also report a tentative detection of a gas-phase emission line of MgS. The ALMA spectrum of this object reveals intriguing features which may be used to investigate chemical processes and dust formation during a high mass-loss phase.
- Publication:
-
Why Galaxies Care About AGB Stars: A Continuing Challenge through Cosmic Time
- Pub Date:
- December 2019
- DOI:
- 10.1017/S1743921318007986
- Bibcode:
- 2019IAUS..343..436J
- Keywords:
-
- stars: AGB and post-AGB;
- circumstellar matter;
- stars: individual (OH 26.5+0.6);
- stars: late-type;
- stars: abundances