Wavelengths and energy levels of singly ionized nickel (Ni ii) measured using fourier transform spectroscopy
Author(s)
Clear, Christian P
Pickering, Juliet C
Nave, Gillian
Uylings, Peter
Raassen, Ton
Type
Journal Article
Abstract
High-resolution spectra of singly ionized nickel (Ni ii) have been recorded using Fourier transform spectroscopy in the region 143–5555 nm (1800–70,000 cm−1) with continuous, nickel–helium hollow cathode discharge sources. An extensive analysis of identified Ni ii lines resulted in the confirmation and revision of 283 previously reported energy levels, from the ground state up to the 3d8(ML)6s subconfigurations. Typical energy-level uncertainties are a few thousandths of a cm−1, representing at least an order-of-magnitude reduction in uncertainty with respect to previous measurements. Twenty-five new energy levels have now been established and are reported here for the first time. Eigenvector compositions of the energy levels have been calculated using the orthogonal operator method. In total, 159 even and 149 odd energy levels and 1424 classified line wavelengths of Ni ii are reported and will enable more accurate and reliable analyses of Ni ii in astrophysical spectra.
Date Issued
2022-08-01
Date Acceptance
2022-07-05
Citation
The Astrophysical Journal Supplement Series, 2022, 261 (2), pp.35-35
ISSN
0067-0049
Publisher
American Astronomical Society
Start Page
35
End Page
35
Journal / Book Title
The Astrophysical Journal Supplement Series
Volume
261
Issue
2
Copyright Statement
© 2022. The Author(s). Published by the American Astronomical Society.
License URL
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council
Identifier
https://iopscience.iop.org/article/10.3847/1538-4365/ac7f9b
Grant Number
ST/K001051/1
ST-N000838
ST/N000838/1
ST/S000372/1
ST/W000989/1
Subjects
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
0306 Physical Chemistry (incl. Structural)
Publication Status
Published
Date Publish Online
2022-08-04