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Related papers: Both accurate and precise gf-values for FeII lines

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We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in…

Astrophysics · Physics 2010-11-11 J. Melendez , N. G. Shchukina , I. E. Vasiljeva , I. Ramirez

Using standard 1D-LTE model atmosphere analysis, we provide an in-depth investigation of iron abundance as derived from neutral and singly ionization iron lines (Fe {\scriptsize{I, II}}) in nearby star clusters. Specifically, we replicate…

Solar and Stellar Astrophysics · Physics 2017-09-06 Patrick D. Aleo , Alexander C. Sobotka , Ivan Ramirez

For the well studied halo star HD 122563 and the four stars in the globular cluster NGC 6397, we determine NLTE abundances of iron using classical plane-parallel model atmospheres. Each star reveals a discrepancy in abundances between the…

Solar and Stellar Astrophysics · Physics 2013-03-05 L. Mashonkina , H. -G. Ludwig , A. Korn , T. Sitnova , E. Caffau

Spectroscopic measurements of iron abundances are prone to systematic modelling errors. We present 3D non-LTE calculations across 32 STAGGER-grid models with effective temperatures from 5000 K to 6500 K, surface gravities of 4.0 dex and 4.5…

Solar and Stellar Astrophysics · Physics 2022-12-12 A. M. Amarsi , S. Liljegren , P. E. Nissen

We present theoretical FeII emission line strengths for physical conditions typical of Active Galactic Nuclei with Broad-Line Regions. The FeII line strengths were computed with a precise treatment of radiative transfer using extensive and…

Astrophysics · Physics 2009-11-07 T. A. A. Sigut , Anil K. Pradhan

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…

We present equivalent widths, improved model atmosphere parameters, and revised abundances for 14 species of 11 elements derived from high resolution optical spectroscopy of 311 metal-poor stars. All of these stars had their parameters…

Solar and Stellar Astrophysics · Physics 2025-02-27 Sanil Mittal , Ian U. Roederer

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…

Astrophysics · Physics 2009-10-30 C. Allende Prieto , R. J. Garcia Lopez

We report on detailed abundances of giants in the Galactic bulge, measured with the HIRES echelle spectrograph on the 10-m Keck telescope. We also review other work on the bulge field population and globular clusters using Keck/HIRES. Our…

Astrophysics · Physics 2015-06-24 R. M. Rich , A. McWilliam

We report the detection of an Al II line at 2669.155 Angstroms in 11 metal-poor stars, using ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We derive Al abundances from this…

Solar and Stellar Astrophysics · Physics 2021-05-19 Ian U. Roederer , James E. Lawler

We report new statistical equilibrium calculations for Fe I and Fe II in the atmosphere of Late-Type stars. We used atomic models for Fe I and Fe II having respectively 256 and 190 levels, as well as 2117 and 3443 radiative transitions.…

Astrophysics · Physics 2016-08-30 F. Thevenin , T. P. Idiart

We report on the results of 18 observations of the core, or peak, of the Fe K emission line at $\sim 6.4$ keV in 15 Seyfert I galaxies using the {\it Chandra} High Energy Grating (HEG). These data afford the highest precision measurements…

Astrophysics · Physics 2009-11-10 Tahir Yaqoob , Urmila Padmanabhan

The lack of FeVII lines in PG1159 stars had led to the conclusion that in some objects iron must be strongly depleted. We have now detected FeX lines in FUSE spectra of the very hottest PG1159 stars Teff=150,000 - 200,000 K; RXJ2117.1+3412,…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. Werner , T. Rauch , J. W. Kruk

In this study, photometric metallicity and absolute magnitude calibrations were derived using F-G spectral type main-sequence stars in the Solar neighbourhood with precise spectroscopic, photometric and Gaia astrometric data for UBV…

Astrophysics of Galaxies · Physics 2019-10-23 M. Celebi , S. Bilir , S. Ak , T. Ak , Z. F. Bostanci , T. Yontan

To calibrate automatic pipelines that determine atmospheric parameters of stars, one needs a sample of stars -- ``benchmark stars'' -- with well defined parameters to be used as a reference We provide a detailed documentation of the…

Atomic transition probability measurements for 364 lines of Ti II in the UV through near IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer and a new echelle spectrometer are combined with…

Solar and Stellar Astrophysics · Physics 2014-02-19 M. P. Wood , J. E. Lawler , C. Sneden , J. J. Cowan

We have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R~38,000) collected with UVES at ESO/VLT either in slit mode (5) or in…

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…

Astrophysics · Physics 2007-05-23 I. G. Nave , S. Johansson , R. C. M. Learner , A. P. Thorne , J. W. Brault

From equivalent widths of the SI lines at 8694 A, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] = 0.5 to 0.7) in six halo stars with [Fe/H] ~ -2.0 suggesting perhaps…

Astrophysics · Physics 2007-05-23 P. E. Nissen , Y. Q. Chen , M. Asplund , M. Pettini

We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda…

Astrophysics · Physics 2009-11-10 Vincent M. Woolf , George Wallerstein