相关论文: Tracing Chemical Depletion in Evolved Binaries Hos…
The detected variety in chemistry and circumstellar shell morphology of the limited sample of Galactic post-AGB stars is so large that there is no consensus yet on how the different objects are linked by evolutionary channels. The…
The comparison of chemical abundances in the neutral gas of galaxies to photospheric abundances of old and young stars, ionized gas abundances, and abundances in galactic halos can trace the chemical enrichment of the universe through…
Binarity is believed to dramatically affect the history and geometry of mass loss in AGB and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars…
Elemental abundance studies of solar twin stars suggest that the solar chemical composition contains signatures of the formation of terrestrial planets in the solar system, namely small but significant depletions of the refractory elements.…
[ABRIDGED]We study the carbon abundances with a twofold objective. On the one hand, we want to evaluate the behaviour of carbon in the context of Galactic chemical evolution. On the other hand, we focus on the possible dependence of carbon…
Context. The chemical processes during the Asymptotic Giant Branch (AGB) evolution of intermediate mass single stars predict most of the observations of the different populations in globular clusters although some important issues still…
The aim of this work is to determine abundances of neutron-capture elements for thin- and thick-disc F, G, and K stars in several sky fields near the north ecliptic pole and to compare the results with the Galactic chemical evolution…
The nearby oxygen-rich AGB star L2 Pup hosts a well-studied nearly edge-on disk. To date, disks around AGB stars have not been chemically studied in detail. By combining a parameterisation commonly used for protoplanetary disks and archival…
Context. The circumstellar environment of evolved stars is generally rich in molecular gas and dust. Typically, the entire environment is either oxygen-rich or carbon-rich, depending on the evolution of the central star. Aims. In this paper…
Variations in chemical abundances with evolutionary phase have been identified among stars in globular and open clusters with a wide range of metallicities. In the metal-poor clusters, these variations compare well with predictions from…
New SiS multi-transition (sub-)millimetre line observations of a sample of AGB stars with varying photospheric C/O-ratios and mass-loss rates are presented. A combination of low- and high-energy lines are important in constraining the…
An ensemble of chemical abundances probing different nucleosynthetic channels can be leveraged to build a comprehensive understanding of the chemical and structural evolution of the Galaxy. Using GALAH DR3 data, we seek to trace the…
The chemical processes during the Asymptotic Giant Branch (AGB) evolution of intermediate mass single stars predict most of the observations of the different populations in Globular Clusters although some important issues still need to be…
The complexity of composite spectra of close binaries makes the study of the individual stellar spectra extremely difficult. For this reason there exists very little information on the chemical composition of high-mass stars in close…
The ``2-process Model'' is a promising technique for interpreting stellar chemical abundance data from large-scale surveys (e.g., SDSS-IV/V, GALAH), enabling more quantitative empirical studies of differences in chemical enrichment history…
Globular cluster stars show chemical abundance patterns typical of hot-CNO processing. Lithium is easily destroyed by proton capture in stellar environments, so its abundance may be crucial to discriminate among different models proposed to…
We investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…
The imprints of stellar nucleosynthesis and chemical evolution of the galaxy can be seen in different stellar populations, with older generation stars showing higher $\alpha$-element abundances while the later generations becoming enriched…
Recent advances in constructing stellar evolution models of hydrogen-deficient post-asymptotic giant branch (AGB) stars are presented. Hydrogen-deficiency can originate from mixing and subsequent convective burning of protons in the deeper…
Aims: We aim to investigate the abundances of light deuterium-bearing species such as HD, H2D+ and D2H+ in a gas-grain chemical model including an extensive description of deuterium and spin state chemistry, in physical conditions…