Related papers: The self-enrichment scenario in intermediate metal…
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 globular clusters. The ages agree well…
We investigate the production of aluminium and the heavy magnesium isotopes in asymptotic giant branch models. We evolve models with a wide range in initial mass (between 1 and 6Msun), and composition (Z=0.02, 0.008, 0.004). We evolve the…
We present a framework that explains the commonly observed variation in light element abundances in globular clusters. If globular clusters form in the centres of dwarf galaxies, they will be pumped onto larger orbits as star formation…
Intermediate mass stellar evolution tracks from the main sequence to the tip of the AGB for five initial masses (2 to 6Msun) and metallicity Z=0.0001 have been computed. The detailed 1D structure and evolution models include exponential…
This work aims to analyze some of the polluters proposed in the self-enrichment scenarios put forward to explain the multiple populations in globular clusters (GCs), extending previous studies. Three scenarios with different polluter stars…
We propose a new chemical evolution model aimed at explaining the chemical properties of globular clusters (GC) stars. Our model depends upon the existence of (i) a peculiar pre-enrichment phase in the GC's parent galaxy associated with…
We have computed detailed evolution and nucleosynthesis models for super and massive AGB stars over the mass range 6.5-9.0 Msun in divisions of 0.5 Msun with metallicities Z=0.02, 0.008 and 0.004. These calculations, in which we find third…
Lithium is made up in the envelopes of massive Asymptotic Giant Branch (AGB) stars through the process of Hot Bottom Burning. In Globular Clusters, this processing is one possible source of the hot-CNO burning whose nuclear products are…
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 further observational test of this finding, we present…
Calculations from stellar evolutionary models of low- and intermediate-mass asymptotic giant branch (AGB) stars provide predictions of elemental abundances and yields for comparison to observations. However, there are many uncertainties…
To better understand the mixing and mass loss experienced by low-mass stars as they ascend the asymptotic giant branch (AGB), I have gathered from the literature the abundances of CNO and s-process elements in post-AGB stars in Galactic…
The origin of abundance spreads observed in omega Centauri is studied in the context of the self-enrichment scenario. Five chemical evolution models are constructed and are compared with empirical metallicity distribution of $\omega$ Cen.…
It is now clear that abundance variations from star-to-star among the light elements, particularly C, N, O, Na and Al, are ubiquitous within galactic globular clusters; they appear seen whenever data of high quality is obtained for a…
We investigate the colour-magnitude relation of metal-poor globular clusters, the 'blue tilt', in the Hydra and Centaurus galaxy clusters and constrain the primordial conditions for star cluster self-enrichment. We analyse U,I photometry…
We focus on the sodium destruction in models reaching the high hot bottom burning temperatures needed to efficiently cycle oxygen to nitrogen in AGB models at the nominal [Fe/H] of the cluster NGC 2808. We increase the initial neon…
The most massive Galactic globular cluster, Omega centauri, appears to have multiple populations. Its bluest main sequence and extended horizontal branch stars are suggested to have the common origin, that is, an extremely high helium…
We explore a scenario where metal-poor globular clusters (GCs) are enriched by the first supernovae in the Universe. If the first stars in a 10^7 Msun dark halo were very massive (>180 Msun), then a pair instability supernova from a single…
We are in the process of testing a popular theory that the observed abundance anomalies in the Globular Cluster NGC 6752 are due to `internal pollution' from intermediate mass asymptotic giant branch stars. To this end we are using a…
The abundance of the neutron-rich magnesium isotopes observed in metal-poor stars is explained quantitatively with a chemical evolution model of the local Galaxy that considers - for the first time - the metallicity-dependent contribution…
The metal content of clusters of galaxies and its relation to their stellar content is revisited making use of a cluster sample for which all four basic parameters are homogeneously measured within consistent radii, namely core-excised…