相关论文: Chemical Evolution of CNO abundances

The formation and evolution of the Milky Way bulge is not yet well understood and its classification is ambiguous. Constraints can, however, be obtained by studying the abundances of key elements in bulge stars. The aim of this study is to…

Understanding the galaxy in which we live is one of the great intellectual challenges facing modern science. With the advent of high quality observational data, the chemical evolution modeling of our galaxy has been the subject of numerous…

We present FOS observations of O III] 1666 A and C III] 1909 A emission in H II regions in dwarf irregular galaxies to measure C/O abundance ratios in those galaxies. We observe a continuous increase in C/O with increasing O/H over the…

We adopt up-to-date yields of 7Li, 13C, 15N from classical novae and use a well tested model for the chemical evolution of the Milky Way in order to predict the temporal evolution of these elemental species in the solar neighborhood. In…

Stellar evolution computations provide the foundation of several methods applied to study the evolutionary properties of stars and stellar populations, both Galactic and extragalactic. The accuracy of the results obtained with these…

The evolution of irregular galaxies is examined from two points of view: on the one hand, models of galactic chemical evolution have been computed and their predictions compared with the corresponding observational data on the element…

Aims. A sample of early B-type stars in OB associations and the field within the solar neighbourhood is studied comprehensively. Present-day abundances for the astrophysically most interesting chemical elements are derived. Methods.…

For $^{12}$C and $^{16}$O, rotating models predict in general enhanced yields. At high metallicity, the carbon and oxygen yields from the very high mass stars, which go through a WR phase, are little affected by rotation. For $^{14}$N,…

We calculate the mean evolution of the iron-peak abundance ratios [(Cr,Mn,Co,Zn)/Fe] in the Galaxy, using modern supernova and hypernova chemical yields and a Galactic Chemical Evolution code that assumes homogeneous chemical evolution. We…

We couple a simplified model for the galactic chemical evolution, with software that models the condensation of dust in protoplanetary disks and software that models the interior structure of planets in order to estimate the effects that…

The basic principles underlying galactic chemical evolution and the most important results of chemical evolution models are discussed. In particular, the chemical evolution of the Milky Way galaxy, for which we possess the majority of…

Abridged: Observed abundances of extremely metal-poor (EMP) stars in the Halo hold clues for the understanding of the ancient universe. Interpreting these clues requires theoretical stellar models at the low-Z regime. We provide the…

Metals -- heavy elements synthesized during various phases of stellar evolution or during supernova explosions -- play a fundamental role in shaping galaxy evolution. In fact, their relative abundances, spatial distribution, and scaling…

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.…

We use the growing data sets of very-metal-poor stars to study the impact of stellar winds of fast rotating massive stars on the chemical enrichment of the early Galaxy. We use an inhomogeneous chemical evolution model for the Galactic halo…

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 present some preliminary results obtained with a new galactic chemodynamical tool under development. In the framework of non-instantaneous recycling approach, we follow the interactions due to star formation and feedback processes. One…

We examine the galactic chemical evolution (GCE) of $^3\rm{He}$ in one-zone and multi-zone models, with particular attention to the stellar yields and GCE parameters that can reproduce both the protosolar $^3\rm{He}$ abundance and recent…

The {\it best} chemical evolution models for the galactic disk computed by different groups with different assumptions are compared with each other and with the observational constraints. Differences and similarities between the models are…

[Abridged] We calculate the structural evolution and nucleosynthesis of a grid of models covering the metallicity range: -6.5 < [Fe/H] < -3.0 (plus Z=0), and mass range: 0.85 < M < 3.0 Msun, amounting to 20 stars in total. In this paper,…