相关论文: Element Abundances through the Cosmic Ages
Review of the history of solar system elemental abundances with a new assessment of elemental and isotopic abundances from CI-chondrites and solar data. Solar elemental abundances, or solar system elemental abundances refer to the…
Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…
The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows…
Constraints on the molecular gas content of galaxies at high redshift are crucial to further our understanding of star formation and galaxy evolution through cosmic times, as molecular gas is the fuel for star formation. Since its initial…
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 evolution of the content of heavy elements in galaxies, the relative chemical abundances, their spatial distribution, and how these scale with various galactic properties, provide unique information on the galactic evolutionary…
The Galaxy is in continuous elemental evolution. Since new elements produced by dying stars are delivered to the interstellar medium, the formation of new enerations of stars and planetary systems is influenced by this metal enrichment. We…
The measurement of chemical abundances in planetary nebulae in nearby galaxies is now relatively straightforward. The challenge is to use these chemical abundances to infer the chemical evolution of their host galaxies. At this point, our…
The heavy elements near QSOs provide unique measures of the star formation and chemical evolution in young galactic nuclei or pre-galactic condensations. Studies of quasar abundances also naturally address a variety of questions regarding…
Spectroscopic observations of distant quasars have resulted in the detection of molecular hydrogen in intervening damped Lyman-alpha absorption clouds (DLAs). We use observations compiled from different experimental groups to show that the…
I discuss recent theoretical work on the formation and evolution of galaxies paying particular attention to the ability of current models to make detailed comparisons with observations of the galaxy population both nearby and at high…
The chemical abundances of metal-poor stars provide a great deal of information regarding the individual nucleosynthetic processes that created the observed elements and the overall process of chemical enrichment of the galaxy since the…
Due to their production sites, as well as to how they are processed and destroyed in stars, the light elements are excellent tools to investigate a number of crucial issues in modern astrophysics: from stellar structure and non-standard…
It is currently impossible to determine the abundances of stellar populations star-by-star in dense stellar systems more distant than a few megaparsecs. Therefore, methods to analyse the composite light of stellar systems are required. I…
The chemical elements are created in nuclear fusion processes in the hot and dense cores of stars. The energy generated through nucleosynthesis allows stars to shine for billions of years. When these stars explode as massive supernovae, the…
Ultraviolet spectra of stars recorded by orbiting observatories since the 1970's have revealed absorption features produced by atoms in their favored ionization stages in the neutral ISM of our Galaxy. Most elements show abundances relative…
Recent abundance measurements in damped Lyman-alpha galaxies, supplemented with unpublished Keck observations, are discussed. The metallicity distribution with cosmic time is examined for clues about the degree of enrichment, the onset of…
An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools…
We have collected an heterogeneous sample of galaxies at redshifts 0.001<z<3.35 with the aim of exploring the evolution of the physical parameters and of the element abundances calculated by modelling the observed spectra. The evolution…
The chemical abundances in the atmosphere of a star provide unique information about the gas from which that star formed, and, modulo processes that are not important for the vast majority of stars, such as mass transfer in close binary…