The influence of Stark broadening on Cr II spectral line shapes in stellar atmospheres

¹ Astronomical Observatory, Volgina 7, 11160 Belgrade 74, Serbia e-mail: mdimitrijevic@aob.bg.ac.yu
² Isaac Newton Institute of Chile, Yugoslavia Branch
³ Institute of Astronomy, Russian Academy of Science, Pyatnitskaya 48, 119017 Moscow, Russia
⁴ Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria

Received: 4 January 2007
Accepted: 12 March 2007

Abstract

Aims.We consider the effect of Stark broadening on the shapes of Cr ii spectral lines observed in stellar atmospheres of the middle part of the main sequence.

Methods.Stark broadening parameters were calculated by the semiclassical perturbation approach. For stellar spectra synthesis, the improved version synth3 of the code synth for synthetic spectrum calculations was used.

Results.Stark broadening parameters for Cr ii spectral lines of seven multiplets belonging to  transitions were calculated. New calculated Stark parameters were applied to the analysis of Cr ii line profiles observed in the spectrum of Cr-rich star HD 133792.

Conclusions.We found that Stark broadening mechanism is very important and should be taken into account, especially in the study of Cr abundance stratification.