Related papers: Galactic Sodium from AGB Stars
We investigate the evolution of the metallicity of the intergalactic medium (IGM) with particular emphasis on its spatial distribution. We propose that metal enrichment occurs as a two step process. First, supernova (SN) explosions eject…
We study the detailed properties of the radial metallicity gradient in the stellar disk of our Galaxy to constrain its chemical and structural evolution. For this purpose we select and analyze $\sim$ 18,500 disk stars taken from two…
We present new theoretical stellar evolutionary models of metal-rich asymptotic giant branch (AGB) stars. Stellar models are evolved with initial masses between 1Msun and 7Msun at Z=0.007, and 1Msun and 8Msun at Z=0.014 (solar) and at…
Trends in the enrichment of elements with stellar ages are a powerful avenue to identify unexplained origins of the elements. We investigate the stellar abundance trends of low to intermediate-mass stars using the GALAH DR3 high-resolution…
A hot plasma is the dominant phase of the interstellar medium of early-type galaxies. Its origin can reside in stellar mass losses, residual gas from the formation epoch, and accretion from outside of the galaxies. Its evolution is linked…
We present follow-up spectroscopy of 21 cataclysmic variables (CVs) with evolved secondaries and ongoing or recently-terminated mass transfer. Evolutionary models predict that the secondaries should have anomalous surface abundances owing…
We present an analytical and phenomenological model for metal enrichment in halos based on hierarchical structure formation. This model assumes that astration of normal stellar populations along with SNe II already occurs at very high…
By means of a detailed chemical evolution model, we follow the evolution of barium and europium in four Local Group Dwarf Spheroidal Galaxies, in order to set constraints on the nucleosynthesis of these elements and on the evolution of this…
From chemical abundance analysis of stars in the Sagittarius dwarf spheroidal galaxy (Sgr), we conclude that the alpha-element deficiencies cannot be due to the Type Ia supernova (SNIa) time-delay scenario of Tinsley (1979). Instead, the…
The warm ionized gas in low-mass, metal-poor starforming galaxies is chemically homogeneous despite the prevalence of large H II regions which contain hundreds of evolved massive stars, supernovae, and Wolf-Rayet stars with…
Dwarf irregular galaxies appear to have undergone very slow chemical evolution since they have low nebular abundances, but have had ongoing star formation over the past 15 Gyr. They are too distant for red giant abundance analyses to…
We have calculated the evolution of low metallicity red giant stars under the assumption of deep mixing between the convective envelope and the hydrogen burning shell. We find that the extent of the observed abundance anomalies, and in…
We study the evolution of extremely metal-poor AGB stars, with metallicities down to [Fe/H]=-5, to understand the main evolutionary properties, the efficiency of the processes able to alter their surface chemical composition and to…
We study the asymptotic giant branch (AGB) evolution of stars with masses between $1~M_{\odot} - 8.5~M_{\odot}$. We focus on stars with a solar chemical composition, which allows us to interpret evolved stars in the Galaxy. We present a…
The internal distribution of heavy elements, in particular the radial metallicity gradient, offers insight into the merging history of galaxies. Using our cosmological, chemodynamical simulations that include both detailed chemical…
Fluorine has many different potential sites and channels of production, making narrowing down a dominant site of fluorine production particularly challenging. In this work, we investigate which sources are the dominant contributors to the…
Galactic globular clusters (GC) are known to have multiple stellar populations and be characterised by similar chemical features, e.g. O-Na anti-correlation. While second-population stars, identified by their Na overabundance, have been…
We develop a hybrid model of galactic chemical evolution that combines a multi-ring computation of chemical enrichment with a prescription for stellar migration and the vertical distribution of stellar populations informed by a cosmological…
The chemical evolution of the Galaxy is followed for the elements affected by neutron capture, in particular for those in the atomic number range 56 to 63 (Ba, La, Ce, Pr, Nd, Sm and Eu). Neutrons by the major 13^C source, released in…
Lithium and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which high resolution optical spectroscopy has been obtained…