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相关论文: Spatially resolved measurements of the solar photo…

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We present solar photospheric abundances for 12 elements from optical and near-infrared spectroscopy. The abundance analysis was conducted employing 3D hydrodynamical (CO5BOLD) as well as standard 1D hydrostatic model atmospheres. We…

太阳与恒星天体物理 · 物理学 2015-05-14 H. -G. Ludwig , E. Caffau , M. Steffen , P. Bonifacio , B. Freytag , R. Cayrel

Solar oxygen abundance measurements based on the O I near-infrared triplet have been a much-debated subject for several decades since non-local thermodynamic equilibrium (NLTE) calculations with 3D radiation-hydrodynamics model atmospheres…

太阳与恒星天体物理 · 物理学 2023-04-12 A. G. M. Pietrow , R. Hoppe , M. Bergemann , F. Calvo

Accurate determination of photospheric solar abundances requires detailed modeling of the solar granulation and accounting for departures from local thermodynamical equilibrium (LTE). We argue that the forbidden C I line at 8727 A is…

天体物理学 · 物理学 2009-11-07 Carlos Allende Prieto , David L. Lambert , Martin Asplund

Our recent re-analysis of the solar photospheric spectra with non-local thermodynamic equilibrium (non-LTE) models resulted in higher metal abundances compared to previous works. When applying the new chemical abundances to Standard Solar…

太阳与恒星天体物理 · 物理学 2022-09-07 Manuel A. Bautista , Maria Bergemann , Helena Carvajal Gallego , Sébastien Gamrath , Patrick Palmeri , Pascal Quinet

We present Herschel PACS spectroscopy of the [O III] 88.4um fine-structure line in the nearby WC8+O binary system gamma Vel to determine its oxygen abundance. The critical density of this line corresponds to several 10^5 R* such that it is…

太阳与恒星天体物理 · 物理学 2024-01-11 Paul A Crowther , M J Barlow , P Royer , D J Hillier , J M Bestenlehner , P W Morris , R Wesson

We performed a compilation of more than 1000 published spectra of HII regions in spiral galaxies. The oxygen and nitrogen abundances in each HII region were recomputed in a homogeneous way, using the P-method. The radial distributions of…

天体物理学 · 物理学 2009-11-10 L. S. Pilyugin , J. M. Vilchez , T. Contini

The debate on the oxygen abundances of metal-poor stars has its origin in contradictory results obtained using different abundance indicators. To achieve a better understanding of the problem we have acquired high quality spectra with the…

天体物理学 · 物理学 2016-08-16 A. E. García Pérez , M. Asplund , F. Primas , P. E. Nissen , B. Gustafsson

The determination of the solar oxygen abundance remains a central problem in astrophysics, as its accuracy is limited not only by models but also by systematics. While many of these factors have been thoroughly characterized, the effect of…

太阳与恒星天体物理 · 物理学 2026-02-11 A. G. M. Pietrow , M. Baratella , I. V. Ilyin , M. Steffen , K. G. Strassmeier

Oxygen is a powerful tracer element of Galactic chemical evolution. Unfortunately, only a few oxygen lines are available in the ultraviolet-infrared stellar spectra for the reliable determination of its abundance. Moreover, oxygen…

太阳与恒星天体物理 · 物理学 2014-09-11 A. Kucinskas , V. Dobrovolskas , P. Bonifacio , E. Caffau , H. -G. Ludwig , M. Steffen , M. Spite

CONTEXT: In recent years, the solar chemical abundances have been studied in considerable detail because of discrepant values of solar metallicity inferred from different indicators, i.e., on the one hand, the "sub-solar" photospheric…

太阳与恒星天体物理 · 物理学 2015-05-13 E. Caffau , E. Maiorca , P. Bonifacio , R. Faraggiana , M. Steffen , H. -G. Ludwig , I. Kamp , M. Busso

We present measurements of the oxygen abundance of the Milky Way's ISM by observing the K-shell X-ray photoionization edge towards galaxy clusters. This effect is most easily observed towards objects with galactic columns (n_H) of a few…

天体物理学 · 物理学 2009-11-13 Wayne H. Baumgartner , Richard F. Mushotzky

The oxygen abundances for four dwarf spiral galaxies have been determined using long-slit spectroscopy. The abundances of these galaxies have not previously reported in the literature. Several HII regions were detected in each galaxy. The…

宇宙学与河外天体物理 · 物理学 2010-11-01 A. M. Hidalgo-Gamez , D. Ramirez-Fuentes , J. J. Gonzalez

Carbon, nitrogen, and oxygen are the fourth, sixth, and third most abundant elements in the Sun. Their abundances remain hotly debated due to the so-called solar modelling problem that has persisted for almost $20$ years. We revisit this…

太阳与恒星天体物理 · 物理学 2021-12-11 A. M. Amarsi , N. Grevesse , M. Asplund , R. Collet

In the Sun, the two forbidden [OI] lines at 630 and 636 nm were previously found to provide discrepant oxygen abundances. aims: We investigate whether this discrepancy is peculiar to the Sun or whether it is also observed in other stars.…

太阳与恒星天体物理 · 物理学 2015-06-15 Elisabetta Caffau , Hans-G. Ludwig , Jean-M. Malherbe , Piercarlo Bonifacio , Matthias Steffen , Lorenzo Monaco

The discrepancy between the oxygen abundances in high-metallicity HII regions determined through the Te-method (and/or through the corresponding "strong lines - oxygen abundance" calibration) and that determined through the model fitting…

天体物理学 · 物理学 2009-11-07 L. S. Pilyugin

We report on the abundance of interstellar neutral oxygen (OI) for 26 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE), the International Spectroscopic Explorer (IUE), and the Hubble Space Telescope (HST). OI…

天体物理学 · 物理学 2009-11-10 Adam G. Jensen , Brian L. Rachford , Theodore P. Snow

We present a new determination of the solar nitrogen abundance making use of 3D hydrodynamical modelling of the solar photosphere, which is more physically motivated than traditional static 1D models. We selected suitable atomic spectral…

太阳与恒星天体物理 · 物理学 2010-11-22 E. Maiorca , E. Caffau , P. Bonifacio , M. Busso , R. Faraggiana , M. Steffen , H. -G. Ludwig , I. Kamp

We present a detailed and uniform study of oxygen abundance from two different oxygen lines at 6158$\AA$ and 6300$\AA$ in a large sample of solar-type stars. The results are used to check the behaviour of these spectral lines as oxygen…

太阳与恒星天体物理 · 物理学 2015-04-15 S. Bertran de Lis , E. Delgado Mena , V. Zh. Adibekyan , N. C. Santos , S. G. Sousa

Aims: To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio. Method: An emission measure method applied to extreme ultraviolet emission lines of Ne IV-VI and O III-V ions observed by the…

天体物理学 · 物理学 2009-11-11 P. R. Young

A solar photospheric "thermal profiling" analysis is presented, exploiting the infrared rovibrational bands of carbon monoxide (CO) as observed with the McMath-Pierce Fourier transform spectrometer (FTS) at Kitt Peak, and from above the…

天体物理学 · 物理学 2009-11-11 Thomas R. Ayres , Claude Plymate , Christoph U. Keller