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Related papers: 6Li/7Li estimates for metal-poor stars

200 papers

We review the Galactic chemical evolution of Li6 and compare these results with recent observational determinations of the lithium isotopic ratio. In particular, we concentrate on so-called standard Galactic cosmic-ray nucleosynthesis in…

Astrophysics · Physics 2009-10-31 Brian D. Fields , Keith A. Olive

Unevolved metal poor stars are the witness of the early evolution of the Galaxy. The determination of their detailed chemical composition is an important tool to understand the chemical history of our Galaxy. The study of their chemical…

Solar and Stellar Astrophysics · Physics 2020-09-30 P. François , S. Wanajo , E. Caffau , N. Prantzos , W. Aoki , M. Aoki , P. Bonifacio , M. Spite , F. Spite

Accurate 7Li(d,n)24He thermonuclear reaction rates are crucial for precise prediction of the primordial abundances of Lithium and Beryllium and to probe the mysteries beyond fundamental physics and the standard cosmological model. However,…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-03 S. Q. Hou , T. Kajino , T. C. L. Trueman , M. Pignatari , Y. D. Luo , C. A. Bertulani

We report Zn abundances for 18 very metal-poor stars studied in our previous work, covering the metallicity range -3.2 < [Fe/H] < -2.5. The [Zn/Fe] values of most stars show an increasing trend with decreasing [Fe/H] in this metallicity…

Solar and Stellar Astrophysics · Physics 2015-05-27 Satoshi Honda , Wako Aoki , Timothy C. Beers , Masahide Takada-Hidai

Theoretical prediction of surface stellar abundances of light elements -- lithium, beryllium, and boron -- represents one of the most interesting open problems in astrophysics. As well known, several measurements of 7-Li abundances in…

Solar and Stellar Astrophysics · Physics 2021-07-07 E. Tognelli , S. Degl'Innocenti , P. G. Prada Moroni , L. Lamia , R. G. Pizzone , A. Tumino , C. Spitaleri , A. Chiavassa

Lithium is an important element for the understanding of ultracool dwarfs because it is lost to fusion at masses above $\sim 68\, M_{\rm J}$. Hence, the presence or absence of atomic Li has served as an indicator of the nearby H-burning…

Solar and Stellar Astrophysics · Physics 2021-09-29 Ehsan Gharib-Nezhad , Mark S. Marley , Natasha E. Batalha , Channon Visscher , Richard S. Freedman , Roxana E. Lupu

We derive atmospheric parameters and lithium abundances for 671 stars and include our measurements in a literature compilation of 1381 dwarf and subgiant stars. First, a "lithium desert" in the effective temperature (Teff) versus lithium…

Solar and Stellar Astrophysics · Physics 2015-06-05 I. Ramirez , J. R. Fish , D. L. Lambert , C. Allende Prieto

Accurate theoretical predictions including leading QED corrections for $2^2P_{1/2} - 2^2S_{1/2}$ (D1) and $2^2P_{3/2} - 2^2S_{1/2}$ (D2) transition energies have been obtained for $^{6,7}$Li isotopes. Our results for the Bethe logarithms…

Atomic Physics · Physics 2015-06-12 M. Puchalski , D. Kedziera , K. Pachucki

The lithium abundance in turnoff stars of the old population of our Galaxy is remarkably constant in the metallicity interval -2.8\textless{}[Fe/H] \textless{}-2.0, defining a plateau. The Li abundance of these turnoff stars is clearly…

Astrophysics of Galaxies · Physics 2015-10-21 Monique Spite , François Spite , Elisabetta Caffau , Piercarlo Bonifacio

The abundance of primordial lithium is derived from the observed spectroscopy of metal-poor stars in the galactic halo. However, the observationally inferred abundance remains at about a factor of three below the abundance predicted by…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-30 G. J. Mathews , A. Kedia , N. Sasankan , M. Kusakabe , Y. Luo , T. Kajino , D. G. Yamazaki , T. Makki , M. El Eid

The light elements up to 7Li were produced by the Standard Big Bang nucleosynthesis (SBBN) in the early universe assuming standard conditions. All observed primordial abundances of these light elements match very well the predicted ones by…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-07 Tahani R. Makki , Mounib F. El Eid , Grant J. Mathews

Extremely metal-poor stars are keys to understand the early evolution of our Galaxy. The ESO large programme TOPoS has been tailored to analyse a new set of metal-poor turn-off stars, whereas most of the previously known extremely…

The Li abundances of the two components of the very metal-poor ([Fe/H]=-2.5) double-lined spectroscopic binary G166-45 (BD+26 2606) are determined separately based on high resolution spectra obtained with the Subaru Telescope High…

Solar and Stellar Astrophysics · Physics 2015-06-04 Wako Aoki , Hiroko Ito , Akito Tajitsu

Lithium abundances in a selected sample of halo stars have been revised by using the new accurate IRFM effective temperatures by Alonso, Arribas & Martinez-Roger (1996a). From 41 plateau stars (Teff > 5700 and [Fe/H] <= -1.5) we found no…

Astrophysics · Physics 2015-06-24 Piercarlo Bonifacio , Paolo Molaro

We present an analysis of 7Li/6Li isotope ratios along four sight lines that probe diffuse molecular gas near the supernova remnant IC 443. Recent gamma-ray observations have revealed the presence of shock-accelerated cosmic rays…

Astrophysics of Galaxies · Physics 2015-06-04 C. J. Taylor , A. M. Ritchey , S. R. Federman , D. L. Lambert

We have computed a grid of up-to-date stellar evolutionary models including atomic diffusion, in order to study the evolution with time of the surface Li abundance in low-mass metal-poor stars. We discuss in detail the dependence of the…

Astrophysics · Physics 2009-11-06 Maurizio Salaris , Achim Weiss

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai…

We provide measurements of the Ba isotopic fractions for five metal-poor stars derived with an LTE analysis using 1D model stellar atmospheres. We use high resolution (R\equiv{\lambda}/\Delta{\lambda}=90000-95000), very high signal-to-noise…

Solar and Stellar Astrophysics · Physics 2015-06-03 A. J. Gallagher , S. G. Ryan , A. Hosford , A. E. Garcia Perez , W. Aoki , S. Honda

We have obtained high-resolution high signal-to-noise spectra of the SI near-infrared doublet at 8694 A in eight metal-poor stars with metallicities in the range -0.6 <[Fe/H]< -3.0. Elemental sulphur abundances were derived for six targets…

Astrophysics · Physics 2009-11-06 Garik Israelian , Rafael Rebolo

Absorption features in stellar atmospheres are often used to calibrate photocentric velocities for kinematic analysis of further spectral lines. The Li feature at $\sim$ 6708 {\AA} is commonly used, especially in the case of young stellar…