Evaluation of the Recent Atomic Data for Fe i Lines Based on Solar and Stellar Spectra

• Published in: Solar physics Vol. 294; no. 11; pp. 1 - 10
• Main Authors: Ryabchikova, T., Piskunov, N., Sitnova, T.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2019; Springer Nature B.V
• Subjects: Abundance; Astronomy; Astrophysics and Astroparticles; Atmospheric Sciences; Chemical elements; Effective temperatures; Experimental data; intensity and diagnostics; Iron; Irradiance Variations of the Sun and Sun-like Stars; Laboratories; Line spectra; Local thermodynamic equilibrium; Physics; Physics and Astronomy; Quality assessment; Solar irradiance; Solar physics; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Spectral line; Spectrum; Spectrum analysis; Stars; Stars & galaxies; Stellar spectra; Sun; Temperature range; Transition probabilities; visible; Solar irradiance; Spectral line, intensity and diagnostics; Spectrum, visible
• ISSN: 0038-0938; 1573-093X; 1573-093X
• DOI: 10.1007/s11207-019-1543-2

We performed an extensive comparative analysis of the recent experimental data on Fe 
i
transition probabilities (TP) based on the observed solar and stellar spectra. This work is part of the Vienna Atomic Line database (VALD) activities. Our motivation is to keep the VALD line list as complete as possible and provide VALD users with substantiated recommendations for the most accurate atomic data. For assessment of data quality we choose the “normal” (as opposed to peculiar and/or magnetic) Main Sequence sharp-line stars of different effective temperatures with accurately known atmospheric parameters: Sun, Procyon, HD 32115, and 21 Peg. Theoretical spectra of these stars were synthesized for 1D plane-parallel model atmospheres accounting for non-local thermodynamic equilibrium (NLTE) effects, and then they were compared with the observations. For all of the stars we derived atmospheric abundances based on the new and previous experimental TP. When using the new TPs the best agreement for iron is achieved with the TP of the Hannover group (Bard, Kock, and Kock,
Astron. Astrophys.
248
, 315,
1991
; Bard and Kock,
Astron. Astrophys.
282
, 1014,
1994
). The Hannover set is recommended as the primary source of transition probabilities in stellar abundance analysis. The new TP data significantly increase the number of spectral lines of Fe 
i
in the optical and red spectral regions available for accurate abundance analysis of stars in a wide range of temperatures and metallicities. Comparison with the observed stellar spectra invalidates some new experimental data despite the small given uncertainty of the laboratory measurements. Finally, we note the importance of accurate line-broadening data.