We have measured the oscillator strength of the Ni I line at 6300.34Å, which is known to be blended with the forbidden [O I] λ6300 line, used for determination of the oxygen abundance in cool stars. We give also wavelengths of the two isotopic line components of 58 Ni and 60 Ni derived from the asymmetric laboratory line profile. These two line components of Ni I have to be considered when calculating a line profile of the 6300Å feature observed in stellar and solar spectra. We also discuss the labelling of the energy levels involved in the Ni I line, as level mixing makes the theoretical predictions uncertain.

We report absolute oscillator strengths for 119 Cr ii transitions in the wavelength region 2050−4850 Å. The transition probabilities have been derived by combining radiative lifetimes, measured with time-resolved laser induced fluorescence, and branching fractions from intensity calibrated Fouirer transform spectrometer data. New radiative lifetimes for the 3d 4 ( 5 D)4p 4 F, 4 D and 6 P terms are reported, adding up to a total of 25 energy levels with measured lifetimes used to derive this improved set of atomic data.

No abstract

No abstract

Experimental branching fractions (BFs) of Mo II, ranging in wavelength from 1970 to 4370 Å, have been measured from intensity calibrated spectra recorded with the Lund UV Fourier transform spectrometer (FTS). Radiative lifetimes for 10 levels have been measured using the method of laser-induced fluorescence (LIF). Combining BFs with new as well as previously measured lifetimes, 16 in total, oscillator strengths of 91 lines were derived. Seven transitions are resonance lines involving the ground state. The BF results are compared with calculations made with the Cowan code and the f-values are compared with previously published data. Improved wavelengths from an ongoing term analysis are also reported.