Identification of SH $Δv=1$ ro-vibrational lines in R And

I. Yamamura; K. Kawaguchi; S. T. Ridgway

doi:10.1086/312420

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Identification of SH $Δv=1$ ro-vibrational lines in R And

I. Yamamura·K. Kawaguchi·S. T. Ridgway

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Abstract

We report the identification of SH $Δv=1$ ro-vibrational lines in the published high-resolution infrared spectrum of the S-type star, R And. This is the first astronomical detection of this molecule. The lines show inverse P-Cygni profiles, indicating infall motion of the molecular layer due to stellar pulsation. A simple spherical shell model with a constant infall velocity is adopted to determine the condition of the layer. It is found that a single excitation temperature of 2200 K reproduces the observed line intensities satisfactory. SH is located in a layer from 1.0 to ~1.1 stellar radii, which is moving inward with a velocity of 9 km s-1. These results are consistent with the previous measurements of CO $Δv=3$ transitions. The estimated molecular abundance SH/H is 1x10^-7, consistent with a thermal equilibrium calculation.

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I. Yamamura, K. Kawaguchi, S. T. Ridgway. 1999-11-05. Identification of SH $Δv=1$ ro-vibrational lines in R And. https://doi.org/10.1086/312420

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