相关论文: An upper limit on the sulphur abundance in HE 1327…

We present a new abundance analysis of HE 1327-2326, the currently most iron-poor star, based on observational data obtained with VLT/UVES. We correct the 1D LTE abundances for 3D effects to provide an abundance pattern that supersedes…

From a newly obtained VLT/UVES spectrum we have determined the oxygen abundance of HE 1327-2326, the most iron-poor star known to date. UV-OH lines yield a 1D LTE abundance of [O/Fe]_OH = 3.7 (subgiant case) and [O/Fe]_OH = 3.4 (dwarf…

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…

Sulfur is important: the site of its formation is uncertain, and at very low metallicity the trend of [S/Fe] against [Fe/H] is controversial. Below [Fe/H]=-2.0, [S/Fe] remains constant or it decreases with [Fe/H], depending on the author…

Sulphur is a volatile alpha-element which is not locked into dust grains in the interstellar medium (ISM). Hence, its abundance does not need to be corrected for dust depletion when comparing the ISM to the stellar atmospheres. The…

Based on spectroscopic constraints derived from NLTE line formation, we explore the likely range of stellar parameters (T_eff and log g) for the hyper-metal-poor (HMP) star HE 1327-2326. Combining the constraints from Balmer line profiles…

We describe the discovery of HE 1327-2326, a dwarf or subgiant with [Fe/H]}=-5.4. The star was found in a sample of bright metal-poor stars selected from the Hamburg/ESO survey. Its abundance pattern is characterized by very high C and N…

Abridged. HE 1327-2326 (HE 1327), with [Fe/H]=-5.2, is one of the most metal-poor stars detected and a candidate to be the offspring of the first stars. Numerous efforts have been made to match its abundance pattern. However, no model…

context : Unlike silicon and calcium, sulphur is an alpha-element which does not form dust. Some of the available observations of the evolution of sulphur with metallicity indicate an increased scatter of sulphur to iron ratios at low…

High resolution UVES spectra of 40 main-sequence stars with -3.3 < [Fe/H] < -1.0 are used to derive S, Fe and Zn abundances from lines in the 400 - 950 nm region. For one star we also present novel observations of the SI triplet at 1.046…

High resolution spectra of 34 halo population dwarf and subgiant stars have been obtained with VLT/UVES and used to derive sulphur abundances from the 8694.0, 8694.6 A and 9212.9, 9237.5 A SI lines. In addition, iron abundances have been…

From equivalent widths of the SI lines at 8694 A, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] = 0.5 to 0.7) in six halo stars with [Fe/H] ~ -2.0 suggesting perhaps…

The main objective of this work is to derive the distribution of the the metal content of HII galaxies using sulphur as an abundance tracer. This increases the metallicity range that can safely be reached. We selected a sample of…

Sulphur is an element which is formed in the alpha-process and is easily measured in the gaseous phase in external galaxies. Since it does not form dust, it is the preferred indicator for alpha-elements, rather than Si or Mg, for which dust…

We have collected from different surveys some significant spectroscopic data observed from star-forming galaxies in the local Universe. The objects showing a relatively rich spectrum in number of lines from different elements were selected…

(Abridged) The abundances of alpha-elements are a powerful diagnostic of the star formation history and chemical evolution of a galaxy. Sulphur, being moderately volatile, can be reliably measured in the interstellar medium (ISM) of damped…

A fraction of the missing sulfur in dense clouds and circumstellar regions could be in the form of three species not yet de- tected in the interstellar medium: H2S2, HS2, and S2 according to experimental simulations performed under…

Context. The Galactic chemical evolution of sulphur is still under debate. At low metallicities some studies find no correlation between [S/Fe] and [Fe/H], others find [S/Fe] increasing towards lower metallicities, and still others find a…

Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding its…

We investigate sulphur abundance in 74 Galactic stars by using high resolution spectra obtained at ESO VLT and NTT telescopes. For the first time the abundances are derived, where possible, from three optical multiplets: Mult. 1, 6, and 8.…