EDP Sciences
Free Access
Volume 409, Number 1, October I 2003
Page(s) 369 - 373
Section Celestial mechanics and astrometry
DOI https://doi.org/10.1051/0004-6361:20031058

A&A 409, 369-373 (2003)
DOI: 10.1051/0004-6361:20031058

Collisional depolarization and transfer rates of spectral lines by atomic hydrogen

II. Application to d states of neutral atoms
M. Derouich1, S. Sahal-Bréchot1 and P. S. Barklem2

1  Observatoire de Paris-Meudon, LERMA UMR CNRS 8112, 5 place Jules Janssen, 92195 Meudon Cedex, France
2  Department of Astronomy and Space Physics, Uppsala University, Box 515, S 751 20 Uppsala, Sweden
    e-mail: Moncef.Derouich@obspm.fr

(Received 28 April 2003 / Accepted 20 June 2003)

The theory of collisional depolarization of spectral lines by atomic hydrogen (Derouich et al. 2003) is extended to d (l=2) atomic levels. Depolarization rates, polarization and population transfer rates are calculated and results are given as a function of the temperature. Cross sections as a function of the effective quantum number for a relative velocity of 10 km s-1 are also given together with velocity exponents $\lambda$, if they exist, with the assumption that the cross section varies with velocity as $v^{-\lambda}$. A discussion of our results is presented.

Key words: Sun: atmosphere -- atomic processes -- line: formation -- polarization

Offprint request: M. Derouich, moncef.derouich@obspm.fr

© ESO 2003