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Related papers: The present-day cosmic phosphorus abundance

200 papers

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…

Astrophysics · Physics 2009-11-07 Carlos Allende Prieto , David L. Lambert , Martin Asplund

The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogenous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in order to discuss the history of star…

Astrophysics · Physics 2007-05-23 Raffaele Gratton , Eugenio Carretta , Francesca Matteucci , Chris Sneden

Non-LTE line formation for Pr II and Pr III is considered through a range of effective temperatures between 7250 K and 9500 K. A comprehensive model atom for Pr II/III is based on the measured and the predicted energy levels, in total, 6708…

Astrophysics · Physics 2009-11-13 L. Mashonkina , T. Ryabchikova , A. Ryabtsev , R. Kildiyarova

A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the…

Astrophysics · Physics 2007-05-23 Edward B. Jenkins

We present a new iron abundance analysis of the hyper metal-poor star HE$~$1327-2326, based on Fe II lines detected in its UV spectral range for the first time. In a Cosmic Origins Spectrograph (COS) spectrum, five new Fe II lines could be…

Solar and Stellar Astrophysics · Physics 2018-08-27 Rana Ezzeddine , Anna Frebel

Aims. The statistical equilibrium of neutral and ionized silicon in the atmospheres of metal-poor stars is discussed. Non-local thermodynamic equilibrium effects are investigated and the silicon abundances in metal-poor stars determined.…

Solar and Stellar Astrophysics · Physics 2015-05-13 J. R. Shi , T. Gehren , L. Mashonkina , G. Zhao

We present new ultra-metal-poor (UMP) stars parameters with [Fe/H]<-4.0 based on line-by-line non-local thermodynamic equilibrium (NLTE) abundances using an up-to-date iron model atom with a new recipe for non-elastic hydrogen collision…

Solar and Stellar Astrophysics · Physics 2017-10-11 Rana Ezzeddine , Anna Frebel , Bertrand Plez

The boron abundances for two young solar-type members of the Orion association, BD -6 1250 and HD 294297, are derived from HST STIS spectra of the B I transition at 2496.771 A. The best-fit boron abundances for the target stars are 0.13 and…

Astrophysics · Physics 2009-10-31 K. Cunha , V. Smith , E. Parizot , D. Lambert

Oxygen abundances are derived in a sample of 13 field F and G dwarfs and subgiants with metallicities in the range of -0.75 < [Fe/H] < +0.15. This is the same sample of stars for which boron abundances have been derived earlier from…

Astrophysics · Physics 2009-11-06 Verne V. Smith , Katia Cunha , Jeremy R. King

Carbon and oxygen abundances in F and G main-sequence stars ranging in metallicity from [Fe/H] = -1.6 to +0.5 are determined from a non-LTE analysis of CI and OI atomic lines in high-resolution spectra. Both C and O are good tracers of…

Astrophysics of Galaxies · Physics 2015-06-16 Poul E. Nissen , William J. Schuster

Recent observations have shown that [P/Fe] in the Galactic stars decreases with increasing [Fe/H] for [Fe/H] > -1 whereas it is almost subsolar for [Fe/H]< -2. These [P/Fe] trends with [Fe/H] have not been well reproduced by previous…

Astrophysics of Galaxies · Physics 2024-05-13 Kenji Bekki , Takuji Tsujimoto

Lithium abundances are presented for a sample of 181 nearby F and G dwarfs with accurate {\it Hipparcos} parallaxes. The stars are on circular orbits about the Galactic centre and, hence, are identified as belonging to the thin disk. This…

Astrophysics · Physics 2009-11-10 David L. Lambert , Bacham E. Reddy

Context. Departures from local thermodynamic equilibrium (LTE) distort the calcium abundance derived from stellar spectra in various ways, depending on the lines used and the stellar atmospheric parameters. The collection of atomic data…

Solar and Stellar Astrophysics · Physics 2019-03-13 Y. Osorio , K. Lind , P. S. Barklem , C. Allende Prieto , Oleg Zatsarinny

We study the formation of O I and OH spectral lines in three-dimensional hydrodynamic models of the solar photosphere. The line source function of the O I 777 nm triplet is allowed to depart from local thermodynamic equilibrium (LTE),…

Astrophysics · Physics 2007-05-23 Dan Kiselman , Åke Nordlund

The Oxygen abundance in the solar photosphere, and consequently the solar metallicity itself, is still a controversial issue with far-reaching implications in many areas of Astrophysics. This paper presents a new determination obtained by…

Solar and Stellar Astrophysics · Physics 2015-04-29 H. Socas-Navarro

We address a long-standing discrepancy between non-LTE analyses of the prominent C II 4267 and 6578/82 A multiplets in early-type stars. A comprehensive non-LTE model atom of C II is constructed based on critically selected atomic data.…

Astrophysics · Physics 2009-11-11 M. F. Nieva , N. Przybilla

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…

Solar and Stellar Astrophysics · Physics 2018-07-04 Ian U. Roederer , Christopher Sneden , James E. Lawler , Jennifer S. Sobeck , John J. Cowan , Ann Merchant Boesgaard

We use new Space Telescope Imaging Spectrograph (STIS) and archival Goddard High Resolution Spectrograph (GHRS) observations to study interstellar B II 1362 and O I 1355 absorption along seven sightlines. Our new column density…

Astrophysics · Physics 2009-10-31 J. Christopher Howk , Kenneth R. Sembach , Blair D. Savage

Aluminium abundances of B-type stars were spectroscopically determined in order to get information about the galactic gas composition at the time of their formation. For this purpose, two AlII lines at 6243 and 4663A were employed. The…

Solar and Stellar Astrophysics · Physics 2025-05-08 Yoichi Takeda

We report the detection, from FUSE data, of phosphorus in the atmospheres of GD71 and two similar DA white dwarfs. This is the first detection of a trace metal in the photosphere of the spectrophotometric standard star GD71. Collectively,…

Astrophysics · Physics 2009-11-13 Paul Dobbie , Martin Barstow , Ivan Hubeny , Jay Holberg , Matt Burleigh , Anne Forbes