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相关论文: The cosmological Lithium problem outside the Galax…

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The standard model of primordial nucleosynthesis by the Big Bang as selected by the WMAP-based estimate of the baryon density ($\Omega_bh^2$) predicts an abundance of $^7$Li that is a factor of three greater than the generally reported…

天体物理学 · 物理学 2009-11-10 David L. Lambert

We investigate lithium depletion in standard stellar models (SSMs) and main sequence (MS) open clusters, and explore the origin of the Li dispersion in young, cool stars of equal mass, age and composition. We first demonstrate that SSMs…

太阳与恒星天体物理 · 物理学 2015-06-18 Garrett Somers , Marc Pinsonneault

Homogeneous abundances of light elements, alpha and Fe-group elements from high-resolution FLAMES spectra are presented for 76 red giant stars in M54, a massive globular cluster (GC) lying in the nucleus of the Sagittarius dwarf galaxy. We…

Observations of interstellar lithium provide a valuable complement to studies of lithium in Pop I and Pop II stars. Large corrections for unseen LiII and for non-gas phase lithium have provided obstacles to using interstellar data for…

天体物理学 · 物理学 2009-10-28 GARY STEIGMAN

We report the discovery of a peculiar set of old super-metal-rich dwarf stars with orbits of low eccentricity that reach a maximum height from the Galactic plane between $\sim$ 0.5-1.5 kpc observed by the \emph{Gaia}-ESO Survey. These stars…

太阳与恒星天体物理 · 物理学 2025-01-29 M. L. L. Dantas , R. Smiljanic , R. Boesso , H. Rocha-Pinto , L. Magrini , G. Guiglion , D. Romano

The discrepancy between the theoretical prediction of primordial lithium abundances and astronomical observations is called the Lithium Problem. We find that extra contributions from non-thermal hydrogen and helium during Big Bang…

宇宙学与河外天体物理 · 物理学 2020-03-31 Ming-Ming Kang , Yang Hu , Hong-Bo Hu , Shou-Hua Zhu

We address the existence and origin of the lithium (Li) desert, a region in the Li - T_eff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late…

太阳与恒星天体物理 · 物理学 2018-06-13 Claudia Aguilera-Gómez , Iván Ramírez , Julio Chanamé

Surface lithium is depleted when a star goes through the first dredge-up phase, yet $1\%$ of red giants are found to be Li-rich. The formation mechanism for these remains uncertain. We combine observational constraints from GALAH Li-rich…

Two problems are discussed here. The first one is the 0.4 dex discrepancy between the 7Li abundance derived from the spectra of metal-poor halo stars on the one hand, and from Big Bang nucleosynthesis, based on the cosmological parameters…

Weak G-band (WGB) stars are a rare class of cool luminous stars that present a strong depletion in carbon, but also lithium abundance anomalies that have been little explored in the literature since the first discovery of these peculiar…

太阳与恒星天体物理 · 物理学 2015-06-03 A. Palacios , M. Parthasarathy , Y. Bharat Kumar , G. Jasniewicz

Previous surveys in a few metal-poor globular clusters (GCs) showed that the determination of abundances for Li and proton-capture elements offers a key tool to address the intracluster pollution scenario. In this Letter, we present Na, O,…

太阳与恒星天体物理 · 物理学 2015-05-18 Valentina D'Orazi , Sara Lucatello , Raffaele Gratton , Angela Bragaglia , Eugenio Carretta , Zhixia Shen , Simone Zaggia , .

Context. About 0.2-2% of giant stars are Li-rich, whose lithium abundance (A(Li)) is higher than 1.5 dex. Among them, near 6% are super Li-rich with A(Li) exceeding 3.2 dex. Meanwhile, the formation mechanism of these Li-rich and super…

太阳与恒星天体物理 · 物理学 2022-12-14 Jun Gao , Chunhua Zhu , Jinlong Yu , Helei Liu , Xizhen Lu , Jianrong Shi , Guoliang Lü

Lithium abundances are presented and discussed for 70 members of the 50 Myr old open cluster alpha Per. More than half of the abundances are from new high-resolution spectra. The Li abundance in the F-type stars is equal to its presumed…

太阳与恒星天体物理 · 物理学 2015-05-19 Suchitra C. Balachandran , Sushma V. Mallik , David L. Lambert

We utilize spectroscopically derived model atmosphere parameters and the \ion{Li}{1} $\lambda6104$ subordinate line and the $\lambda6708$ doublet to derive lithium abundances for 12 members of the Upper-Centaurus Lupus (UCL) and…

太阳与恒星天体物理 · 物理学 2015-06-03 Eric J. Bubar , Marc Schaeuble , Jeremy R. King , Eric E. Mamajek , John R. Stauffer

We present the first systematic study of lithium abundance in a chemically homogeneous sample of 27 red supergiants (RSGs) in the young Perseus complex. For these stars, accurate stellar parameters and detailed chemical abundances of iron…

太阳与恒星天体物理 · 物理学 2022-06-06 C. Fanelli , L. Origlia , A. Mucciarelli , N. Sanna , E. Oliva , E. Dalessandro

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…

星系天体物理 · 物理学 2015-10-21 Monique Spite , François Spite , Elisabetta Caffau , Piercarlo Bonifacio

Observations of low-metallicity halo stars have revealed a puzzling result: the abundance of \li7 in these stars is at least three times lower than their predicted primordial abundance. It is unclear whether the cause of this disagreement…

星系天体物理 · 物理学 2015-06-12 Tijana Prodanovic , Tamara Bogdanovic , Dejan Urosevic

This study investigates the temporal and spatial variations in lithium abundance within the Milky Way using a sample of 22,034 main-sequence turn-off (MSTO) stars and subgiants, characterised by precise stellar ages, 3D NLTE (non-local…

星系天体物理 · 物理学 2024-11-21 Tiancheng Sun , Shaolan Bi , Xunzhou Chen , Yuxi , Lu , Yuqin Chen , Ming-Yi Ding , Jianrong Shi , Hongliang Yan , Zhishuai Ge

I summarize the results of 15 years of research on the surface abundances of stars in globular clusters. Globular-cluster stars afford a unique view of the physical processes that shape the surface abundances of stars on and beyond the…

太阳与恒星天体物理 · 物理学 2021-11-02 A. J. Korn

Using the cosmological constants derived from WMAP, the standard big bang nucleosynthesis (SBBN) predicts the light elements primordial abundances for 4He, 3He, D, 6Li and 7Li. These predictions are in satisfactory agreement with the…

宇宙学与河外天体物理 · 物理学 2012-08-13 M. Spite , F. Spite , P. Bonifacio