搜索结果: 1-15 共查到“天体物理学 abundance”相关记录21条 . 查询时间(0.043 秒)
An abundance study of red-giant-branch stars in the Hercules dwarf spheroidal galaxy
red-giant-branch stars the Hercules dwarf spheroidal galaxy
2011/1/11
Using high-resolution spectroscopy, we provide a determination of [Fe/H] and [Ca/H] for confirmed red-giant branch member stars of the Hercules dwarf spheroidal galaxy. Based on this we explore the ag...
The chemical abundances of metal-poor stars are an excellent test bed by which to set new constraints on models of neutron-capture processes at low metallicity. Some r-process-rich (hereafter r-rich) ...
Effects of rotation and magnetic fields on the lithium abundance and asteroseismic properties of exoplanet-host stars
magnetic fields the lithium abundance asteroseismic properties
2011/1/11
Aims: The effects of rotation and magnetic fields on the surface abundances of solar-type stars are studied in order to investigate whether the reported difference in lithium content of exoplanet-host...
The chemical composition of the Orion star-forming region: II. Stars, gas, and dust: the abundance discrepancy conundrum
the Orion star-forming region II. Stars
2011/1/13
We re-examine the recombination/collisional emission line (RL/CEL) nebular abundance discrepancy problem in the light of recent high-quality abundance determinations in young stars in the Orion star-f...
As one of the most powerful probes of cosmological structure formation, the abundance of massive galaxy clusters is a sensitive probe of modifications to gravity on cosmological scales. In this paper,...
Spectroscopic observations of a sample of dwarf spiral galaxies. II- Abundance gradients
dwarf spiral galaxies Abundance gradients
2010/11/10
The oxygen gradient of four dS galaxies has been determined using abundances for several
Hii regions determined with four different methods. The gradient slopes of the three non-barred
galaxies in t...
The Elemental Abundance Distributions of Milky Way Satellite Galaxies
Elemental Abundance Distributions Milky Way Satellite Galaxies
2010/11/11
The chemical compositions of the stars in Milky Way (MW)satellite galaxies reveals the history of gas flows and star formation (SF)intensity. This talk presented a Keck/DEIMOS spectroscopic survey of ...
Abundance determination in HII regions from spectra without the [OII]3727+3729 line
galaxies abundances – ISM abundances – Hii regions
2010/11/11
We suggest an empirical calibration for determination of oxygen and nitrogen abundances and
electron temperature in Hii regions where the [Oii]3727+3729 line (R2) is not available.
The calibration...
Abundance Patterns in S-type AGB stars : Setting Constraints on Nucleosynthesis and Stellar Evolution Models
Abundance Patterns Setting Constraints Stellar Evolution Models
2010/11/12
During the evolution on the AGB, S-type stars are the first objects to experience s-process nucleosynthesis and third dredge-ups, and therefore to exhibit sprocess signatures in their atmospheres.
Solar twins in M67 : Evolutionary status and lithium abundance
Stars fundamental parameters – Stars abundances – Stars evolution – Stars interiors – Stars solar-type
2010/11/11
Aims. We determine the age and mass of the three best solar twin candidates in open cluster M67 through lithium evolutionary models.Methods. We computed a grid of evolutionary models with non-standard...
Abundance anomalies in pre-main-sequence stars: Stellar evolution models with mass loss
Diffusion — stars chemically peculiar — stars mass–loss — stars pre–main-sequence — stars evolution — stars
2010/11/12
Aims. The effects of atomic diffusion on internal and surface abundances of A and F pre–main-sequence stars with mass loss are studied in order to determine at what age the effects materialize, as wel...
Determining the forsterite abundance of the dust around AGB stars
forsterite abundance of the dust AGB stars
2010/11/11
We present a diagnostic tool to determine the forsterite abundance of the dust ejected by AGB stars. Our method is based on a comparison between the observed strength of spectral bands of forsterite a...
Chemical abundance ratios of galactic globular clusters from modelling integrated light spectroscopy
galactic globular clusters light spectroscopy
2011/1/10
We use our new, flux-calibrated stellar population model of absorption-line indices to derive ages, metallicities, and various element abundance ratios from integrated light spectroscopy of galactic g...
Flux-calibrated stellar population models of Lick absorption-line indices with variable element abundance ratios
Flux-calibrated stellar population models Lick absorption-line indices
2011/1/10
We present new stellar population models of Lick absorption-line indices with variable element abundance ratios. The models are based on our new calibrations of absorption-line indices with stellar pa...
The SEGUE Stellar Parameter Pipeline. V. Estimation of Alpha-Element Abundance Ratios From Low-Resolution SDSS/SEGUE Stellar Spectra
Instrumentation and Methods for Astrophysics (astro-ph.IM)
2011/1/5
We present a method for the determination of [alpha/Fe] ratios from low-resolution (R = 2000) SDSS/SEGUE stellar spectra.