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相关论文: New Fe I level energies and line identifications f…

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The spectrum of neutral iron is critical to astrophysics, yet furnace laboratory experiments cannot reach many high-lying Fe I levels. Instead, Peterson & Kurucz (2015) and Peterson, Kurucz & Ayres (2017) turned to UV and optical spectra of…

太阳与恒星天体物理 · 物理学 2022-06-29 Ruth C. Peterson , Robert L. Kurucz

The spectra of B-type and early A-type stars show mumerous unidentified lines in the whole optical range, especially in the 5100-5400 A interval. Because Fe II transitions to high energy levels should be observed in this region, we used…

太阳与恒星天体物理 · 物理学 2010-07-12 Fiorella Castelli , Robert L. Kurucz

The spectra of B-type and early A-type stars show numerous unidentified lines in the whole optical range, especially in the 5100 - 5400 A interval. Because Fe II transitions to high energy levels should be observed in this region, we used…

太阳与恒星天体物理 · 物理学 2015-05-19 F. Castelli , R. L. Kurucz

Many energy levels of singly ionised iron (Fe II, $Z=26$) remain uncertain or experimentally unknown. Their identification and spectral line data are required in reliable astrophysical spectral analyses. In motivation for improving the…

原子物理 · 物理学 2024-08-16 M. Ding , H. Kozuki , F. Concepcion , G. Nave , J. C. Pickering

We have recorded spectra of iron-neon and iron-argon hollow cathode lamps in the region 1700A -- 5um (59000 -- 2000cm-1), with Fourier transform (FT) spectrometers at the National Solar Observatory, Tucson, Arizona, U.S.A. and Imperial…

天体物理学 · 物理学 2007-05-23 I. G. Nave , S. Johansson , R. C. M. Learner , A. P. Thorne , J. W. Brault

The analysis of the high-resolution UVES spectra of the CP stars HR 6000 and 46 Aql revealed the presence of an impressive number of unidentified lines, in particular in the 5000 - 5400 A region. Because numerous 4d-4f transitions of FeII…

太阳与恒星天体物理 · 物理学 2015-05-14 F. Castelli , R. L. Kurucz , S. Hubrig

New improvements in the measurement of both the optical solar spectrum and laboratory wavelengths for lines of neutral iron are combined to extract central wavelength shifts for 1446 lines observed in the Sun. This provides the largest…

天体物理学 · 物理学 2009-10-30 C. Allende Prieto , R. J. Garcia Lopez

A comprehensive model atom for Fe with more than 3000 energy levels is presented. As a test and first application of this model atom, Fe abundances are determined for the Sun and five stars with well determined stellar parameters and…

太阳与恒星天体物理 · 物理学 2015-05-27 L. Mashonkina , T. Gehren , J. -R. Shi , A. J. Korn , F. Grupp

Neutral Fe lines are the most abundant in the spectrum of late stars. They are used to obtain different basic stellar parameters such as relative abundances, surface gravity, and effective temperature. However, the centers of many of these…

太阳与恒星天体物理 · 物理学 2024-05-07 M. C. Vieytes

We develop a new method to determine oscillator strength values of atomic absorption lines with state-of-the-art detailed spectral synthesis calculations of the optical spectrum of the Sun and of standard spectral reference stars. We update…

太阳与恒星天体物理 · 物理学 2015-05-20 A. Lobel

New radiative lifetimes, measured to $\pm$ 5 % accuracy, are reported for 31 even-parity levels of Fe I ranging from 45061 cm$^{-1}$ to 56842 cm$^{-1}$. These lifetimes have been measured using single-step and two-step time-resolved…

太阳与恒星天体物理 · 物理学 2015-06-23 E. A. Den Hartog , M. P. Ruffoni , J. E. Lawler , J. C. Pickering , K. Lind , N. R. Brewer

Stellar absorption lines of heavy elements can give us various insights into the chemical evolution of the Galaxy and nearby galaxies. Recently developed spectrographs for the near-infrared wavelengths are becoming more and more powerful…

A detailed study of emission lines from Fe VII, Fe VIII and Fe IX observed by the EUV Imaging Spectrometer on board the Hinode satellite is presented. Spectra in the ranges 170-212 A and 246-292 A show strongly enhanced lines from the upper…

太阳与恒星天体物理 · 物理学 2015-05-13 P. R. Young , E. Landi

Neutral Fe lines in metal-poor stars yield conflicting abundances depending on whether and how deviations from local thermodynamic equilibrium (LTE) are considered. We have collected new high resolution and high signal-to-noise ultraviolet…

太阳与恒星天体物理 · 物理学 2018-07-04 Ian U. Roederer , Christopher Sneden , James E. Lawler , Jennifer S. Sobeck , John J. Cowan , Ann Merchant Boesgaard

We report new experimental Fe I oscillator strengths obtained by combining measurements of branching fractions measured with a Fourier Transform spectrometer and time-resolved laser-induced fluorescence lifetimes. The study covers the…

太阳与恒星天体物理 · 物理学 2017-11-01 M. T. Belmonte , J. C. Pickering , M. P. Ruffoni , E . A. Den Hartog , J. E. Lawler , A. Guzman , U. Heiter

We gathered more than 1130 high-resolution optical spectra for more than 250 Galactic classical Cepheids. The spectra were collected with different optical spectrographs: UVES at VLT, HARPS at 3.6m, FEROS at 2.2m MPG/ESO, and STELLA. To…

The advent of new and more powerful infrared spectrographs has significantly motivated the advancement of the study of atomic and molecular line lists and stellar atmosphere models. While optical abundance determinations rely on extensively…

With new astronomical infrared spectrographs the demands of accurate atomic data in the infrared have increased. In this region there is a large amount of parity-forbidden lines, which are of importance in diagnostics of low-density…

天体物理学 · 物理学 2008-11-26 M. Aldenius , S. Johansson

We report new branching fractions for 121 UV lines from the low-lying odd-parity levels of Fe II belonging to the z6Do, z6Fo, z6Po, z4Fo, z4Do and z4Po terms of the 3d6(5D)4p configuration. These lines range in wavelength from 2250 - 3280…

太阳与恒星天体物理 · 物理学 2019-08-21 E. A. Den Hartog , J. E. Lawler , C. Sneden , J. J. Cowan , A. Brukhovesky

We present theoretical iron emission line strengths for physical conditions typical of Active Galactic Nuclei with Broad-Line Regions. The non-local thermodynamic equilibrium (NLTE) models include a new and extensive treatment of radiative…

天体物理学 · 物理学 2009-11-10 T. A. A. Sigut , Anil K. Pradhan , Sultana N. Nahar
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