Related papers: Solar origins: Place and Chemical Composition
We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) both with stellar parameters and Galactic orbital parameters…
We study the origin of iron and alpha-elements (O, Mg, Si) in clusters of galaxies. In particular, we discuss the [O/Fe] ratio and the iron mass-to-luminosity ratio in the intracluster medium (ICM) and their link to the chemical and…
We have used high-resolution spectra obtained with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to derive kinematic properties and chemical abundances of Fe, O, Mg and Si for 89 stars in…
The Sun exhibits a depletion in $^{17,18}$O relative to $^{16}$O by 6 % compared to the Earth and Moon$^{1}$. The origin of such a non-mass-dependent isotope fractionation has been extensively debated since the three-isotope-analysis$^{2}$…
Determinations of the \he3 concentrations in Galactic matter serve to impose interesting and important constraints both on cosmological models and on models of Galactic chemical evolution. At present, observations of \he3 in the solar…
We present a comparison between the [Ca,C,N/Fe]-mass relations observed in local spheroids and the results of a chemical evolution model which already successfully reproduces the [Mg/Fe]-mass and the [Fe/H]-mass relations in these systems.…
New infrared absorption measurements of oxygen isotope ratios in CO gas from individual young stellar objects confirm that the solar system is anomalously high in its 18O/17O ratio compared with extra-solar oxygen in the Galaxy. We show…
The chemical composition of galaxies offers vital insights into their formation and evolution. In particular, the relationship between helium abundance (He/H) and metallicity serves as a key diagnostic for estimating the primordial helium…
To understand the chemical origin of the Solar system, the chemical evolution along the star/planet formation is a key issue. Extensive observational studies have demonstrated a chemical diversity in young low-mass protostellar sources so…
Determining the He/H ratio in cool stars presents a fundamental astrophysical challenge. While this ratio is established for hot O and B stars, its extrapolation to cool stars remains uncertain due to the absence of helium lines in their…
We investigate the chemical evolution of odd-numbered elements such as sodium (Na) and aluminum (Al) during the early epochs of the Galactic halo with the use of a model that reproduces the observed box-shaped distribution of extremely…
We analyse C$^{18}$O ($J=3-$2) data from a sample of 99 infrared-bright massive young stellar objects (MYSOs) and compact HII regions that were identified as potential molecular-outflow sources in the Red MSX source (RMS) survey. We extract…
Heterogeneous supernova debris formed the solar system. Cores of inner planets formed in the central iron rich region. The Sun formed on the collapsed supernova core. Lighter elements and the lighter isotopes of each element are enriched at…
We analyse two recent computations of type II supernova nucleosynthesis by Woosley & Weaver (1995, WW95) and Thielemann, Nomoto, & Hashimoto (1996, TNH96), focusing on the ability to reproduce the observed [Mg/Fe]-ratios in various galaxy…
We discuss the chemical properties of a sample of UV-selected intermediate-redshift (0 < z < 0.4) galaxies in the context of their physical nature and star formation history. This work represents an extension of our previous studies (Treyer…
Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc of the Sun. The abundances are obtained from the fitting of…
3He-rich solar energetic particles (SEPs) are believed to be accelerated in solar flares or jets by a mechanism that depends on the ion charge-to-mass (Q/M) ratio. It implies that the flare plasma characteristics (e.g., temperature) may be…
Using the standard infall model of Galactic chemical evolution, we explore the origin of carbon and calculate the abundance evolution of CNO elements for 8 different models of stellar nucleosynthesis yields. The results show that, in the…
We study the evolution of the [O/Fe]-[Fe/H] relation and the dependence of the iron abundance on distance from the galactic plane z in a one-zone model for a disk galaxy, starting from the beginning of star formation (Wiebe98). We obtain…
Carbon (C) is thought to be produced by both core collapse supernovae (CCSN) and asymptotic giant branch (AGB) stars, but the relative contributions of these two sources are uncertain. We investigate the astrophysical origin of C using…