The Spectrum and Term Analysis of Co ii

Abstract

High-resolution spectra of singly ionized cobalt have been recorded by Fourier transform spectrometry in the region 1420-33333 Å (70422-3000 cm -1 ) with cobalt-neon and cobalt-argon hollow cathode lamps as sources. Most of the Co II lines exhibit broadening due to hyperfine structure, but the wavenumber uncertainty for the center of gravity of the strongest lines is less than 0.002 cm -1 . Of the previously listed energy levels of Co II , 215 have been revised and six have been discarded. In addition, 171 new levels have been found of which 125 are reported here for the first time. The number of classified lines has doubled with wavenumbers and classifications being presented for 2373 Co II lines, of which 1242 involve the new levels.