New Ritz Wavelengths and Transition Probabilities for Parity-Forbidden, Singly Ionised Nickel [Ni ii] Lines of Astrophysical Interest Christian P.

Published

December 12, 2022

Author(s)

Christian P. Clear, Peter Uylings, Ton Raassen, Gillian Nave, Juliet C. Pickering

Abstract

We report accurate Ritz wavelengths for parity-forbidden [Ni ii] transitions, derived from energy levels determined using high-resolution Fourier transform spectroscopy. Transitions between the 17 lowest Ni ii energy levels of even parity produced Ritz wavelengths for 116 parity-forbidden lines. Uncertainties for the Ritz wavelengths derived in this work are typically two orders of magnitude lower than previously published values. Transition probabilities were calculated using the semi-empirical orthogonal operator method, with uncertainties ranging from approximately 1% for strong M1 lines and up to 10% for weak E2 lines. Accurate forbidden line wavelengths and transition probabilities, particularly for lines in the IR, are important in the analyses of low-density astrophysical plasmas, such as supernova remnants, planetary nebulae and active galactic nuclei.

Citation

Monthly Notices of the Royal Astronomical Society

Volume

519

Pub Type

Journals

Download Paper

https://doi.org/10.1093/mnras/stac3739

Local Download

Keywords

atomic data, line identifications, atomic spectroscopy

Citation

Clear, C. , Uylings, P. , Raassen, T. , Nave, G. and Pickering, J. (2022), New Ritz Wavelengths and Transition Probabilities for Parity-Forbidden, Singly Ionised Nickel [Ni ii] Lines of Astrophysical Interest Christian P., Monthly Notices of the Royal Astronomical Society, [online], https://doi.org/10.1093/mnras/stac3739, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935246 (Accessed October 8, 2025)