Improved HCN/HNC linelist, model atmospheres and synthetic spectra for WZ Cas |
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| Authors: | G J Harris J Tennyson B M Kaminsky Ya V Pavlenko H R A Jones |
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| Institution: | Department of Physics and Astronomy, University College London, London WC1E 6BT;Main Astronomical Observatory, National Academy of Sciences, Zabolotnoho 27, Kyiv-127 03680, Ukraine;Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB |
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| Abstract: | We build an accurate data base of 5200 HCN and HNC rotation–vibration energy levels, determined from existing laboratory data. 20 000 energy levels in the Harris et al. linelist are assigned approximate quantum numbers. These assignments, lab-determined energy levels and Harris et al. energy levels are incorporated in to a new energy level list. A new linelist is presented, in which frequencies are computed using the lab-determined energy levels where available, and the ab initio energy levels otherwise.
The new linelist is then used to compute new model atmospheres and synthetic spectra for the carbon star WZ Cas. This results in better fit to the spectrum of WZ Cas in which the absorption feature at 3.56 μm is reproduced to a higher degree of accuracy than has previously been possible. We improve the reproduction of HCN absorption features by reducing the abundance of Si to Si/H]=?0.5 dex, however, the strengths of the Δ v = 2 CS band heads are overpredicted. |
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| Keywords: | molecular data stars: AGB stars: atmospheres stars: carbon infrared: stars |
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