EDP Sciences
Free access
Volume 446, Number 1, January IV 2006
Page(s) 367 - 372
Section Atomic, molecular and nuclear data
DOI http://dx.doi.org/10.1051/0004-6361:20053919

A&A 446, 367-372 (2006)
DOI: 10.1051/0004-6361:20053919

Improved low-temperature rate constants for rotational excitation of CO by H $_\mathsf{2}$

M. Wernli1, P. Valiron1, A. Faure1, L. Wiesenfeld1, P. Jankowski2 and K. Szalewicz3

1  Laboratoire d'Astrophysique de Grenoble, UMR 5571 CNRS-UJF, OSUG, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
    e-mail: michael.wernli@obs.ujf-grenoble.fr
2  Department of Quantum Chemistry, Institute of Chemistry, Nicholaus Copernicus University, Gagarina 7, 87-100 Torun, Poland
3  Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA

(Received 26 July 2005 / Accepted 12 September 2005)

Cross sections for the rotational (de)excitation of CO by ground state para- and ortho-H2 are obtained using quantum scattering calculations for collision energies between 1 and 520 cm-1. A new CO-H2 potential energy surface is employed and its quality is assessed by comparison with explicitly correlated CCSD(T)-R12 calculations. Rate constants for rotational levels of CO up to 5 and temperatures in the range 5-70 K are deduced. The new potential is found to have a strong influence on the resonance structure of the cross sections at very low collision energies. As a result, the present rates at 10 K differ by up to 50% with those obtained by Flower (2001) on a previous, less accurate, potential energy surface.

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

© ESO 2006

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.