EDP Sciences
Free access
Volume 406, Number 2, August I 2003
Page(s) 759 - 764
Section Celestial mechanics and astrometry
DOI http://dx.doi.org/10.1051/0004-6361:20030695

A&A 406, 759-764 (2003)
DOI: 10.1051/0004-6361:20030695

Experimental transition probabilities and Stark shifts in O III and O IV spectra

S. Djenize1, 2, 3, S. Bukvic1, 2, A. Sreckovic1, 2 and S. Kalezic1

1  Faculty of Physics, University of Belgrade 11001 Belgrade, POB 368, Serbia
2  Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade, Serbia
3  Hungarian Academy of Sciences, Budapest, Hungary

(Received 31 January 2003 / Accepted 23 April 2003)

On the basis of the relative line intensity ratio (RLIR) method transition probability values of the spontaneous emission (Einstein's A values) of 41 astrophysically important transitions (in 15 multiplets) in the doubly (O III) and 7 transitions (in 5 multiplets) in triply (O IV) ionized oxygen spectra have been obtained relative to the reference A values related to the 326.085 nm O III and 340.355 nm O IV, most intensive transitions in the O III and O IV spectra. Fourteen of the investigated O III lines belong to the cascades in the astrophysically important Bowen fluorescence mechanism. Most of the O III transition probability values are the first data obtained experimentally using the RLIR method. Stark shift values (d) of the mentioned lines are also measured. Twenty three of them were not known and represent the first data in this field. Our A and d values are compared to available experimental and theoretical data. A linear, low-pressure, pulsed arc was used as an optically thin plasma source operated in oxygen discharge at a 42 000 K electron temperature and $1.65 \times
10^{23}$  m -3 electron density.

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

Offprint request: S. Djenize, steva@ff.bg.ac.yu

© ESO 2003