Tracing the evolution of NGC 6397 through the chemical composition of its stellar populations

  title={Tracing the evolution of NGC 6397 through the chemical composition of its stellar populations},
  author={Karin Lind and Corinne Charbonnel and Thibault Decressin and Francesca Primas and Frank Grundahl and Martin Asplund},
  journal={Astronomy and Astrophysics},
Context. The chemical compositions of globular clusters provide important information on the star formation that occurred at very early times in the Galaxy. In particular the abundance patterns of elements with atomic number z ≤ 13 may shed light on the properties of stars that early on enriched parts of the star-forming gas with the rest-products of hydrogen-burning at high temperatures. Aims. We analyse and discuss the chemical compositions of a large number of elements in 21 red giant branch… Expand
Chemical analysis of eight giant stars of the globular cluster NGC 6366
The metal-rich Galactic globular cluster NGC 6366 is the fifth closest to the Sun. Despite its interest, it has received scarce attention, and little is known about its internal structure. ItsExpand
Atomic diffusion and mixing in old stars - V. A deeper look into the globular cluster NGC 6752
Context. Abundance trends in heavier elements with evolutionary phase have been shown to exist in the globular cluster NGC 6752 ([Fe/H] = −1.6). These trends are a result of atomic diffusion andExpand
Fluorine abundances and the puzzle of globular cluster chemical history
The abundance of fluorine in a few Galactic globular clusters is known to strongly vary from star-to-star. These unexpected chemical properties are an additional confirmation of the chemicalExpand
Atomic diffusion and mixing in old stars VI: The lithium content of M30
The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among theExpand
Insights into the chemical composition of the metal-poor Milky Way halo globular cluster NGC 6426
We present our detailed spectroscopic analysis of the chemical composition of four red giant stars in the halo globular cluster NGC 6426. We obtained high-resolution spectra using the Magellan2/MIKEExpand
Multiple stellar populations in globular clusters with photometry and low resolution spectroscopy
Our view of Globular Clusters has deeply changed in the last decade. Modern spectroscopic and photometric data have conclusively established that globulars are neither coeval nor monometallic,Expand
Chemical composition of the outer halo globular cluster Palomar 15
Globular clusters (GCs) in the outer Milky Way halo are important tracers of the assembly history of our Galaxy. Only a few of these objects show spreads in heavier elements beyond the canonicalExpand
A differential chemical element analysis of the metal poor Globular Cluster NGC 6397
We present chemical abundances in three red giants and two turn-off stars in the metal poor Galactic globular cluster (GC) NGC 6397 based on spectroscopy obtained with the MIKE high resolutionExpand
We used three sets of high-resolution spectra acquired with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to investigate the chemical and kinematicalExpand
Formation of Multiple Populations in Globular Clusters: constraints on the dilution by pristine gas
The star-to-star differences in the abundance of light elements observed in the globular clusters (GCs) can be explained assuming that a second generation (SG) of stars form in the gas ejected by theExpand


Abundances in giant stars of the globular cluster NGC 6752
Recent theoretical yields and chemical evolution models demonstrate that intermediate-mass AGB stars cannot reproduce the observed abundance distributions of O, Na, Mg, and Al. As a furtherExpand
Origin of the abundance patterns in Galactic globular clusters: constraints on dynamical and chemical properties of globular clusters
Aims. We analyse the effects of a first generation of fast rotating massive stars on the dynamical and chemical properties of globular clusters. Methods. We use stellar models of fast rotatingExpand
Nitrogen Abundances in Giant Stars of the Globular Cluster NGC 6752
We present N abundances for 21 bright giants in the globular cluster NGC 6752 based on high-resolution UVES spectra of the 3360 A NH lines. We confirm that the Stromgren -->c1 index traces the NExpand
First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
In the framework of the ESO Large Programme "First Stars", very high-quality spectra of some 70 very metal-poor dwarfs and giants were obtained with the ESO VLT and UVES spectrograph. These stars areExpand
Atomic Diffusion and Mixing in Old Stars. I. Very Large Telescope FLAMES-UVES Observations of Stars in NGC 6397
We present a homogeneous photometric and spectroscopic analysis of 18 stars along the evolutionary sequence of the metal-poor globular cluster NGC 6397 ([Fe/H] ≈ -2), from the main-sequence turnoffExpand
Properties of stellar generations in globular clusters and relations with global parameters
We revise the scenario of the formation of Galactic globular clusters (GCs) by adding the observed detailed chemical composition of their different stellar generations to the set of their globalExpand
Abundance Variations within Globular Clusters
▪ Abstract Abundance variations within globular clusters (GCs), and of GC stars with respect to field stars, are important diagnostics of a variety of physical phenomena, related to the evolution ofExpand
On the self-enrichment scenario of galactic globular clusters: constraints on the IMF
Aims. Galactic globular cluster (GC) stars exhibit abundance patterns that are not shared by their field counterparts, e.g. the welldocumented O-Na and Mg-Al anticorrelations. Recent spectroscopicExpand
New light on stellar abundance analyses: Departures from LTE and homogeneity.
▪ Abstract The information on the chemical compositions of stars encoded in their spectra plays a central role in contemporary astrophysics. Stellar element abundances are, however, not observed: toExpand
The fraction of second generation stars in globular clusters from the analysis of the horizontal branch
The majority of globular clusters show chemical inhomogeneities in the composition of their stars, apparently due to a second stellar generation in which the forming gas is enriched by hot-CNO cycledExpand