EDP Sciences
Free Access
Volume 393, Number 2, October II 2002
Page(s) 721 - 726
Section Atomic and molecular data
DOI https://doi.org/10.1051/0004-6361:20021174

A&A 393, 721-726 (2002)
DOI: 10.1051/0004-6361:20021174

Ion contribution to the astrophysical important 447.15, 587.56 and 667.82 nm He I spectral lines broadening

V. Milosavljevic1, 2 and S. Djenize1, 2, 3

1  Faculty of Physics, University of Belgrade, PO Box 368, Belgrade, Serbia, Yugoslavia
2  Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade, Yugoslavia
3  Hungarian Academy of Sciences, Budapest, Hungary

(Received 16 May 2002 / Accepted 9 August 2002 )

Characteristics of the astrophysical important Stark broadened 447.15 nm, 587.56 nm and 667.82 nm $\ion{He}{i}$ spectral line profiles have been measured at electron densities between 0.3 $\times$10 $^{\rm 22}$ and 8.2 $\times$10 $^{\rm 22}$ m $^{\rm -3}$ and electron temperatures between 8000 and 33 000 K in plasmas created in five various discharge conditions using a linear, low-pressure, pulsed arc as an optically thin plasma source operated in a helium-nitrogen-oxygen gas mixture. On the basis of the observed asymmetry of the line profiles we have obtained their ion broadening parameters ( A) caused by influence of the ion microfield on the line broadening mechanism and also the influence of the ion dynamic effect ( D) on the line shape. Our A and D parameters represent the first data obtained experimentally by the use of the line profile deconvolution procedure. We have found stronger influence of the ion contribution to these $\ion{He}{i}$ line profiles than the semiclassical theoretical approximation provides. This can be important for some astrophysical plasma modeling or diagnostics.

Key words: plasmas -- line: profiles -- atomic data

Offprint request: V. Milosavljevic, vladimir@ff.bg.ac.yu

SIMBAD Objects

© ESO 2002