Stark broadening and hfs of Mn II

Abstract

Large differences between previous calculations of the Mn II spectral line Stark widths [Popović, L.Č., Dimitrijević, M.S., 1997a. A&AS 128, 203; Popović, L.Č., Dimitrijević, M.S., 1997b. SAJ 156, 173] and a recent experiment by [Djeniže, S., Bukvić, S., Srećković, A., Nikolić, Z., 2006. NewA 11, 256] are considered. In order to do so, new semiclassical perturbation calculations of the Stark broadening parameters of three spectral lines within Mn II 3d54s a7S-3d54p z7Po and three within Mn II 3d54s a5S-3d54p z5Po multiplets, are performed. The influence of hfs on the Stark broadening parameters determination as a possible reason of disagreement is also discussed, on the example of Mn II 260.6455 nm and 259.4497 nm lines. Namely, measured and calculated values taking into account the hfs effect are compared. We found that this effect cannot explain the large discrepancy between experiment and theory. Other possible reasons for disagreement like the configuration interaction are discussed as well. The new semiclassical perturbation calculations, more sophisticated than previous ones, performed by using the modified semiempirical theory, are in better agreement with experiment, but a large difference up to a factor 2.39 for the width, still exist. © 2007.