Quantum Stark widths of Se III–VI lines

Abstract

Stark broadening for 19 spectral lines of several selenium ions (four Se III lines, eight Se IV lines, three Se V lines and four Se VI lines) have been calculated using our quantum mechanical method. Many lines among them have been recently discovered for the first time in the ultraviolet spectrum of the hot white dwarf (WD) RE 0503−289 and in the atmospheres of the cool DO white dwarfs HD 149499 B and HZ 21. This recent discovery prompts us to calculate the Stark widths of the new lines. Stark widths of only three Se III lines have been compared to the available modified semi-empirical results. We could not find Stark broadening data for the other considered lines. Two calculation stages are carried out before the Stark broadening evaluation: we calculate the atomic structure as a first step, and then we calculate the collision electron–ion as a second step. We present our results for the considered lines at different temperature values and at an electron density Ne=1017 cm−3. The obtained results are useful for the modelling of stellar atmospheres. They will also enter the database of Stark broadening parameters: STARK-B.