EDP Sciences
Free Access
Volume 408, Number 3, September IV 2003
Page(s) 1197 - 1203
Section Celestial mechanics and astrometry
DOI https://doi.org/10.1051/0004-6361:20030969

A&A 408, 1197-1203 (2003)
DOI: 10.1051/0004-6361:20030969

Collisional excitation rates of H $\mathsf{_2}$O with H $\mathsf{_2}$

II. Rotational excitation with ortho-H $\mathsf{_2}$ at very low temperature and application to cold molecular clouds
A. Grosjean1, M.-L. Dubernet2 and C. Ceccarelli3

1  Laboratoire d'Astrophysique, UMR CNRS 6091, Observatoire de Besançon, Université de Franche-Comté, 41 bis avenue de l'Observatoire, BP 1615, 25010 Besançon Cedex, France
2  LERMA FRE 2460, Observatoire de Paris, Section de Meudon, 5 place Janssen, 92195 Meudon Cedex, France
3  Laboratoire d'Astrophysique de l'Observatoire de Grenoble, 414 rue de la Piscine, BP 53, 38041 Grenoble Cedex 9, France

(Received 13 March 2003 / Accepted 12 June 2003)

We present the results of close coupling calculations of pure rotational excitation rate coefficients of H 2O by ortho-H 2, performed between 5 K and 20 K. At 20 K there is a good agreement with those results obtained previously by Phillips et al. (1996). Fits of our de-excitation collisional rate coefficients are provided. These new rate coefficients are used in the modelling of cold interstellar clouds to determine the influence of the precision of the rate coefficients on predicted line intensities.

Key words: molecular data -- molecular processes -- ISM: molecules

Offprint request: M.-L. Dubernet, marie-lise.dubernet@obspm.fr

© ESO 2003