Experimental atomic data of spectral lines – I. Cs, Ba, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Re, and Os in the 370–1000 nm interval

ABSTRACT Atomic data are fundamental for plasma diagnostics in laboratory and astrophysics through spectroscopy. These data are extensively present in data bases for light elements, however incomplete for high-mass atoms. This paper presents the results of systematic spectroscopy of 17 elements with high Z, expected to be produced in kilonova events generated by neutron star mergers, whose spectral lines are not yet fully identified in stellar spectra and fusion devices. Experimental data are from échelle high-resolution (λ/Δλ = 60 000) spectroscopy of hollow cathode lamps obtained with the Catania Astrophysical Observatory Spectropolarimeter covering the 3700–10 000 Å range in a single exposure. A total of about 7700 spectral lines with energy level classification not previously listed in the NIST, Kurucz, and VALD data bases are here reported for neutral and singly ionized atomic transitions. For the spectral lines of any species, we report the measured wavelengths and their relative intensities. If possible, we also estimate the transition probabilities under the assumptions of optically thin emission and electric-dipole transitions. These are converted into oscillator strengths ready to be inserted in astrophysical data bases for spectral synthesis.