English
Related papers

Related papers: The Galactic evolution of sulphur as traced by glo…

200 papers

We present evidence for the contribution of high-mass globular clusters to the stellar halo of the Galaxy. Using SDSS-II/SEGUE spectra of over 1900 G- and K-type halo giants, we identify for the first time a subset of stars with CN…

Astrophysics of Galaxies · Physics 2015-05-19 Sarah L. Martell , Eva K. Grebel

Although globular clusters are generally chemically homogeneous, substantial abundance variations are sometimes seen even among unevolved main sequence stars, especially for the CNO group of elements. Multi-object intermediate-dispersion…

Astrophysics · Physics 2007-05-23 Russell Cannon , Gary Da Costa , John Norris , Laura Stanford , Barry Croke

Dramatic recent progress in understanding galactic chemical evolution (GCE) has been driven partly by direct observations of the distant past with HST and JWST of stellar abundances from giant high-resolution spectroscopic surveys (APOGEE,…

Astrophysics of Galaxies · Physics 2025-02-19 David H. Weinberg

[ABRIDGED] Metal-rich globular clusters provide important tracers of the formation of our Galaxy. Moreover, and not less important, they are very important calibrators for the derivation of properties of extra-galactic metal-rich stellar…

Astrophysics · Physics 2009-11-13 S. Feltzing , F. Primas , R. A. Johnson

Galactic chemical evolution models which include sodium from type II supernovae alone underestimate the abundance of sodium in the interstellar medium by a factor of two to three over about 3 dex in metallicity and predict a flat behaviour…

Astrophysics · Physics 2007-05-23 Robert G. Izzard , Brad K. Gibson , Richard J. Stancliffe

We conducted an investigation on the chemical abundances of 4,316 stars in the red giant branch (RGB) phase from the recently released APO-K2 catalogue. Our aim was to characterize the abundance trends of the single elements with…

Astrophysics of Galaxies · Physics 2024-07-09 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

We have previously reported on chemical abundance trends with evolutionary state in the globular cluster NGC 6397 discovered in analyses of spectra taken with FLAMES at the VLT. Here, we reinvestigate the FLAMES-UVES sample of 18 stars,…

Solar and Stellar Astrophysics · Physics 2012-09-24 T. Nordlander , A. J. Korn , O. Richard , K. Lind

Fluorine is a fairly good tracer of formation histories of multiple stellar populations in globular clusters as already revealed by several studies. Large variations in fluorine abundance in red giant stars of the globular cluster M22 have…

Solar and Stellar Astrophysics · Physics 2015-06-17 P. de Laverny , A. Recio-Blanco

We have derived Mn abundances for more than 200 stars in 19 globular clusters. In addition, Mn abundance determinations have been made for a comparable number of halo field and disk stars possessing an overlapping range of metallicities and…

We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 S. S. Larsen , J. P. Brodie , J. Strader

The uncertainties which still plague our understanding of the evolution of the light nuclides D, 3He and 4He in the Galaxy are described. Measurements of the local abundance of deuterium range over a factor of 3. The observed dispersion can…

Astrophysics of Galaxies · Physics 2015-05-14 Donatella Romano

We have used high-resolution, high signal-to-noise spectra obtained with the VLT and UVES to determine abundances of 17 elements in 4 red giants in the Sculptor dwarf spheroidal galaxy. Our [Fe/H] values range from --2.10 to --0.97,…

We present a chemical composition analysis of 36 giants in the nearby mildy metal-poor (<[Fe/H]> = -1.18) "CN-bimodal" globular cluster M4. Confronted with a cluster that has large and variable interstellar extinction across the cluster…

The chemical evolution of fluorine is still a matter of debate in Galactic archaeology, especially at low metallicities, where it is particularly challenging to obtain the corresponding chemical abundances from observations. We present here…

Astrophysics of Galaxies · Physics 2025-11-03 Valeria Grisoni , Federico Rizzuti , Gabriele Cescutti

We determine relative abundance ratios for the neutron-capture elements Zr, La, Ce, Nd, and Eu for a sample of 27 Galactic dwarf stars with -1.5 < [Fe/H] <-0.8. We also measure the iron-peak element Sc. These stars separate into three…

Solar and Stellar Astrophysics · Physics 2017-01-18 C. K. Fishlock , D. Yong , A. I. Karakas , A. Alves-Brito , J. Melendez , P. E. Nissen , C. Kobayashi , A. R. Casey

We take advantage of the Gaia-ESO Survey iDR4 bulge data to search for abundance anomalies that could shed light on the composite nature of the Milky Way bulge. The alpha-elements (Mg, Si, and whenever available, Ca) abundances, and their…

The metallicity distribution function (MDF) of the Galactic bulge features a multi-peak shape, with a metal-poor peak at [Fe/H]=-0.3 dex and a metal-rich peak at [Fe/H]=+0.3 dex. This bimodality is also seen in [alpha/Fe] versus [Fe/H]…

Astrophysics of Galaxies · Physics 2024-05-22 M. Molero , F. Matteucci , E. Spitoni , A. Rojas-Arriagada , R. M. Rich

The globular cluster HP~1 is projected at only 3.33 degrees from the Galactic center. Together with its distance, this makes it one of the most central globular clusters in the Milky Way. It has a blue horizontal branch (BHB) and a…

Solar and Stellar Astrophysics · Physics 2016-06-22 B. Barbuy , E. Cantelli , A. Vemado , H. Ernandes , S. Ortolani , I. Saviane , E. Bica , D. Minniti , B. Dias , Y. Momany , V. Hill , M. Zoccali , C. Siqueira-Mello

Abundances of five elements, Na, Mg, Al, Si, and Sr, are investigated for 44 very metal-poor stars (-4.0 < [Fe/H] < -1.5) in the Galactic halo system based on an Local Thermodinamic Equilibrium (LTE) analysis of high-resolution…

We review Galactic halo formation theories and supporting evidence, in particular kinematics and detailed chemical abundances of stars in some relevant globular clusters as well as Local Group dwarf galaxies. Outer halo red HB clusters tend…

Astrophysics · Physics 2009-11-13 Doug Geisler , George Wallerstein , Verne V. Smith , Dana I. Casetti-Dinescu