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Related papers: Sulphur abundances in Terzan 7

200 papers

We present new determinations of the iron abundance for 220 stars belonging to the stellar system Terzan 5 in the Galactic bulge. The spectra have been acquired with FLAMES at the Very Large Telescope of the European Southern Observatory…

For the first time, the sulphur abundance relative to hydrogen (S/H) in the Narrow Line Regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission line intensities…

We have performed new determinations of sulphur and silicon abundances for a sample of 26 disk stars based on high-resolution, high signal-to-noise spectra. The results indicate a solar [S/Fe] for [Fe/H] >-0.3, below which [S/Fe] increases…

Astrophysics · Physics 2009-11-07 Y. Q. Chen , P. E. Nissen , G. Zhao , M. Asplund

We propose an empirical sulphur abundance determination method based on the strong sulphur emission lines, [S II] 6716, 6731 and [S III] 9069, 9531 in H II regions. From a compilation of literature data we have made a calibration of sulphur…

Astrophysics · Physics 2007-05-23 Tina Christensen , Lars Petersen , Peter Gammelgaard

We investigate the debated "sulphur discrepancy" found among metal-poor stars of the Galactic halo with [Fe/H] < -2. This discrepancy stems in part from the use of two different sets of sulphur lines, the very weak triplet at 8694-95 A and…

Astrophysics · Physics 2016-08-30 Andreas J. Korn , Nils Ryde

Massive globular clusters (GCs) contain at least two generations of stars with slightly different ages and clearly distinct light elements abundances. The Na-O anticorrelation is the best studied chemical signature of multiple stellar…

We used near-infrared spectroscopy at medium-high resolution (R=8,000$-$25,000) to perform the first comprehensive chemical study of the intermediate luminosity bulge globular cluster Terzan~6. We derived detailed abundances and abundance…

Astrophysics of Galaxies · Physics 2024-06-12 C. Fanelli , L. Origlia , A. Mucciarelli , F. R. Ferraro , R. M. Rich , B. Lanzoni , D. Massari , C. Pallanca , E. Dalessandro , M. Loriga

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

Using the NIRSPEC spectrograph at Keck II, we have obtained infrared echelle spectra covering the range $1.5-1.8 \mu \rm m$ for the highly reddened bulge globular clusters Terzan 4 and Terzan 5. The clusters are of interest because a blue…

Astrophysics · Physics 2009-11-10 Livia Origlia , R. Michael Rich

Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc of the Sun. The abundances are obtained from the fitting of…

Astrophysics · Physics 2009-11-07 S. Daflon , K. Cunha , V. V. Smith , K. Butler

Context. Sulfur (S) is one of the lesser-studied $\alpha$-elements. Published investigations of its behavior have so far focused on local stars, and only a few clusters of the Milky Way have been considered to study this topic. We aim to…

Astrophysics of Galaxies · Physics 2023-03-22 F. Lucertini , L. Monaco , E. Caffau , A. Mucciarelli , S. Villanova , P. Bonifacio , L. Sbordone

It is still debated whether or not the Galactic chemical evolution of sulphur in the halo followed the constant or flat trend with [Fe/H], ascribed to the result of explosive nucleosynthesis in type II SNe. The aim of this study is to try…

Astrophysics of Galaxies · Physics 2015-05-27 H. Jönsson , N. Ryde , P. E. Nissen , R. Collet , K. Eriksson , M. Asplund , B. Gustafsson

Sulfur abundances are derived for a sample of ten B main-sequence star members of the Orion association. The analysis is based on LTE plane-parallel model atmospheres and non-LTE line formation theory by means of a self-consistent spectrum…

Solar and Stellar Astrophysics · Physics 2015-05-14 Simone Daflon , Katia Cunha , Ramiro de la Reza , Jon Holtzman , Cristina Chiappini

This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in Type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential…

Astrophysics · Physics 2009-11-06 K. B. Kwitter , R. B. C. Henry

We have compiled a sample of globular clusters with high quality stellar abundances from the literature to compare to the chemistries of stars in the Galaxy and those in dwarf spheroidal galaxies. Of the 45 globular clusters examined, 29…

Astrophysics · Physics 2008-11-26 Barton J. Pritzl , Kim A. Venn , Mike J. Irwin

Due to their volatile nature, when sulfur and zinc are observed in external galaxies, their determined abundances represent the gas-phase abundances in the interstellar medium. This implies that they can be used as tracers of the chemical…

In the present work we used a grid of photoionization models combined with stellar population synthesis models to derive reliable Ionization Correction Factors (ICFs) for the sulphur in star-forming regions. These models cover a large range…

Astrophysics of Galaxies · Physics 2016-01-20 O. L. Dors , E. Perez-Montero , G. F. Hagele , M. V. Cardaci , A. C. Krabbe

The RESIK instrument on {\em CORONAS-F} spacecraft observed several sulphur X-ray lines in three of its four channels covering the wavelength range 3.8-6.1 \AA\ during solar flares. The fluxes are analyzed to give the sulphur abundance.…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. Sylwester , B. Sylwester , K. J. H. Phillips , V. D. Kuznetsov

We present the abundance analyses of three isolated A-type supergiant stars in the dwarf irregular galaxy Sextans A from high-resolution spectra the UVES spectrograph at the VLT. Detailed model atmosphere analyses have been used to…

We present preliminary iron abundances and $\alpha$ element (Ca, Mg) abundance ratios for a sample of 22 Red Giant Branch (RGB) Stars in the Sagittarius dwarf spheroidal galaxy (Sgr), selected near the RGB-Tip. The sample is representative…

Astrophysics · Physics 2007-05-23 Lorenzo Monaco