Experimental radiative lifetimes for highly excited states and calculated oscillator strengths for lines of astrophysical interest in singly ionized cobalt (Co ii)

Abstract

This work reports new experimental radiative lifetimes and calculated oscillator strengths for transitions of astrophysical interest in singly ionized cobalt. More precisely, nineteen radiative lifetimes in Co + have been measured with the time-resolved laser-induced fluorescence technique using one-and two-step excitations. Out of these, seven belonging to the high lying 3d 7 ( 4 F)4d configuration in the energy range 90697 -93738 cm −1 are new, and the other twelve from the 3d 7 ( 4 F)4p configuration with energies between 45972 and 49328 cm −1 are compared with previous measurements. In addition, a relativistic Hartree-Fock model including core-polarization effects has been employed to compute transition rates. Supported by the good agreement between theory and experiment for the lifetimes, new reliable transition probabilities and oscillator strengths have been deduced for 5080 Co ii transitions in the spectral range 114 -8744 nm.

Experimental transition probabilities for 4p – 4d spectral lines in V II

“…The present paper is part of an ongoing project where lifetimes of high excitation levels in the iron-group elements are measured (Engström et al 2014;Hartman et al 2015Hartman et al , 2017Lundberg et al 2016;Quinet et al 2016).…”

The Belgian repository of fundamental atomic data and stellar spectra (BRASS)

“…Uncertainty in atomic data has led to several recent efforts, and many more ongoing, to update the atomic data of many ions with much-needed experimental data required for quantitative spectroscopy , (Lawler et al 2015), (Pehlivan et al 2015), (Ruffoni et al 2015), (Belmonte et al 2017). In addition, many more theoretical transitions are available due to increasingly more complex atomic calculations (Deb & Hibbert 2014), (Ruczkowski et al 2014), (Bouazza et al 2015), (Castelli et al 2016), (Quinet et al 2016). Online repositories such as the Vienna atomic line database, (Ryabchikova et al 2015), the national institute of standards and technology atomic spectra database, (Kramida et al 2015), and the providers within the virtual atomic and molecular data centre, (Dubernet et al 2016), have made the retrieval of atomic line lists from the literature a much simpler task.…”

Application of Laboratory Atomic Physics to Some Significant Stellar Chemical Composition Questions

“…Several atomic physics groups are making major contributions to improving transition data through many theoretical and laboratory approaches. These groups and some representative publications include, but are not limited to, those at: The University of Mons [8,9]; Imperial College London [10,11]; Lund University [12,13]; and Uppsala University [7,14]. Our collaboration from The University of Wisconsin-Madison and The University of Texas at Austin has concentrated on improving these basic line parameters through laboratory experiments, and applying these lab data to classes of stars most relevant to Galactic chemical evolution descriptions.…”