Importance of collisions with charged particles for stellar UV line shapes:
Astronomical Observatory, Volgina 7, 11160 Belgrade, Serbia and Montenegro
2 Isaac Newton Institute of Chile, Yugoslavia Branch
Corresponding author: N. Milovanović, firstname.lastname@example.org
Accepted: 10 November 2003
Stark broadening parameters, widths and shifts, for 84 spectral lines of doubly-ionized cadmium () have been calculated using the modified semi-empirical approach (MSE). Calculated spectral lines belong to the transitions 4d95s–4d95p and 4d95p–4d95d. Widths and shifts of the spectral lines are given for temperature range of 5000 K–60 000 K and an electron density of 1023 m-3. The influence of collisions with charged particles on UV stellar lines along the HR diagram is discussed. Compared to the Doppler broadening, the influence of the Stark broadening mechanism is more important for deeper atmospheric layers and for larger values of . Stark broadening does not depend on turbulent velocity for the considered stellar model of a standard main sequence hot star of A0 spectral type. The influence of the Stark widths for standard models of DA and DB white dwarfs is also discussed.
Key words: atomic processes / line: formation / stars: atmospheres / stars: early-type / stars: white dwarfs
© ESO, 2004