Results 271 to 280 of about 63,862 (294)

Abundance measurements in stellar environments

AIP Conference Proceedings, 2014
Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit.
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From Stellar Spectra to Abundances

Astrophysics and Space Science, 2001
The current techniques of stellar abundances determination from high resolution spectra are discussed, and the related uncertainties arising from the analysis are examined. These involve the observational uncertainties but also physical data, and atmosphere models accuracy. This critical assessment is then used to shed light on the controversial [O/Fe]
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Abundance ratios in quasi-stellar objects

Astrophysics and Space Science, 1977
Relative abundances of carbon and aluminium with respect to silicon have been calculated in the QSOs PHL957, PKS0237-23, 1331+170, 3C191 and M132. Relative abundance of Fe with respect to Mg has been also calculated in the QSOs 1331+170 and PHL938. The ratiosN(C)/N(Si),N(Al)/N(Si) andN(Fe)/N(Mg) in QSOs considered as a class are (5.5±1.6), (0.13±0.03 ...
R. K. Thakur, P. K. Mishra
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Stellar nucleosynthesis and galactic abundances

AIP Conference Proceedings, 2001
Galactic abundances are neither constant in time nor do they evolve in a simple fashion, e.g., by an enrichment of heavy elements in constant relative proportions. Instead, their evolution in space and time reflects the history of star formation and the lifetimes of the diverse contributing stellar objects.
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Elemental abundances for stellars-process studies

Astrophysics and Space Science, 1987
Nuclear reaction network calculations of heavy element enhancements are tabulated for different values of the mean neutron exposure τ0. These tables are useful for comparison with observeds-process abundance patterns which appear to span a wide range in τ0.
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Stellar Abundances — First Generation to Solar

AIP Conference Proceedings, 2006
The discovery and analysis of metal‐poor stars lead to insight into conditions when the Universe and Galaxy were young. We present the rationale for studying such objects (which become progressively rarer at lowest abundance), with a description of their systematic discovery, culminating in the recent analysis of two objects having [Fe/H] < −5.0.
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Stellar abundance

Nature, 1995
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sMILES SSPs: a library of semi-empirical MILES stellar population models with variable [α/Fe] abundances

Monthly Notices of the Royal Astronomical Society, 2023
Adam Thomas Knowles, Anne E Sansom, Alejandro Vazdekis   +2 more
exaly  

New Light on Stellar Abundance Analyses: Departures from LTE and Homogeneity

Annual Review of Astronomy and Astrophysics, 2005
Martin Asplund
exaly  

Abundance Determinations from Stellar Spectra

Annual Review of Astronomy and Astrophysics, 1966
R. Cayrel, G. Cayrel de Strobel
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