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Session 103 - Cool Stars.
Display session, Thursday, January 18
North Banquet Hall, Convention Center

[103.14] Hot Water in Cool Stars

S. Viti (UCL), H. R. A. Jones (LJMU), J. Tennyson, O. L. Polyansky, S. Miller (UCL), P. Hauschildt (ASU), F. Allard (WSU)

We compare high quality data of the infrared water vapour bands for one of the coolest known M dwarfs, TVLM 513-46546 with synthetic spectra from the model atmosphere code \scPHOENIX. We show how the use of three different datasets for the water vapour input to the model produces dramatic changes to the synthetic spectra yet none account for the observations. These comparisons underline the urgent need for more accurate data for water vapour.

We have calculated a preliminary water linelist computed with parameters suitable for Sunspots. The codes employed calculate quantum mechanically the rotation-vibration energy levels, wavefunctions and associated dipole transition strengths using the \scDVR3D program suite. This water linelist improves on the previous one because it uses a better potential and the full symmetry of the water molecule. However, so far the energy levels computed are limited to the ground vibrational state. Using these calculations we have compared our results with linestrengths measured in laboratory experiments performed at a temperature of 1823K and the agreement is very good.

We are calculating a more complete water linelist. It will include all energy levels up to 30 000 cm^-1 for angular momentum states up to J=30 and it uses an accurate potential surface. First results from this production are already available. Progress on these projects will be reported at the conference.

Program listing for Thursday