High-J v=0 SiS Maser Emission in IRC +10216: A New Case of Infrared Overlaps
Abstract
We report on the first detection of maser emission in the J=11-10, J=14-13, and J=15-14 transitions of the v=0 vibrational state of SiS toward the carbon-rich star IRC +10216. These masers seem to be produced in the very inhomogeneous region between the star and the inner dust formation zone, located at ~=(5-7)R*, with expansion velocities below 10 km s-1. We interpret the pumping mechanism as being due to overlaps between v=1-0 rovibrational lines of SiS and mid-IR lines of C2H2, HCN, and their 13C isotopologues. The large number of overlaps found suggest the existence of strong masers for high-J v=0 and v=1 SiS transitions, located in the submillimeter range. In addition, it could be possible to find several rotational lines of the SiS isotopologues displaying maser emission.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2006
- DOI:
- 10.1086/507104
- arXiv:
- arXiv:0710.1836
- Bibcode:
- 2006ApJ...646L.127F
- Keywords:
-
- Stars: Circumstellar Matter;
- Masers;
- Stars: AGB and Post-AGB;
- Stars: Carbon;
- Astrophysics
- E-Print:
- 4 pages, 1 figure, published in the ApJ Letters