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 C-rich star IRC+10216. These masers seem to be produced in the very inhomogeneous region between the star and the inner dust formation zone, placed at 5-7 R*, with expansion velocities below 10 km/s. We interpret the pumping mechanism as due to overlaps between v=1-0 ro-vibrational lines of SiS and mid-IR lines of C2H2, HCN and their 13C isotopologues. The large number of overlaps found suggests 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.

4 pages, 1 figure, published in the ApJ Letters

References in corpus (1)

• SiO in C-rich circumstellar envelopes of AGB stars: effects of non-LTE chemistry and grain adsorption

Cited by in corpus (26)

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• Discovery of SiCSi in IRC+10216: A missing link between gas and dust carriers of SiC bonds
• A spectral line survey in the 2 mm and 1.3 mm windows toward the carbon rich envelope of IRC +10216
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• Tentative detection of phosphine in IRC+10216
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• The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216
• Mapping the Linearly Polarized Spectral Line Emission around the Evolved Star IRC+10216
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• SiS in the circumstellar envelope of IRC +10126: maser and quasi-thermal emission
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• Multi-line study of the radial extent of SiO, CS, and SiS in AGB envelopes
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• IRC+10216 mass loss properties through the study of $\lambda$3mm emission: Large spatial scale distribution of SiO, SiS, and CS
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