Related papers: Chemical Evolution of Galaxies
Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the masses of the…
Stellar chemical element ratios have well-defined systematic trends as a function of abundance, with an excellent correlation of these trends with stellar populations defined kinematically. This is remarkable, and has significant…
In this review we present a brief discussion on the observational evidence in favor of the presence of temperature variations, and conclude that many planetary nebulae show spatial temperature variations that are larger than those predicted…
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…
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…
In this series of lectures I discuss the basic principles and the modelling of the chemical evolution of galaxies. In particular, I present models for the chemical evolution of the Milky Way galaxy and compare them with the available…
While the chemical abudances observed in bright planetary nebulae in local spiral galaxies are less varied than their counterparts in dwarfs, they provide new insight. Their helium abundances are typically enriched by less than 50\%…
The chemical composition of high-redshift galaxies is an important property that gives clues to their past history and future evolution. Measuring abundances in distant galaxies with current techniques is often a challenge, and the…
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…
Adopting a single-zone framework, with accretion of primordial gas on a free-fall timescale, the chemical evolution of the Galactic bulge is calculated, assuming (i) a corresponding rapid timescale for star formation, and (ii) an initial…
Radial metallicity gradients are observed in the disks of the Milky Way and in several other spiral galaxies. In the case of the Milky Way, many objects can be used to determine the gradients, such as HII regions, B stars, Cepheids, open…
The predictions of the multiple burst accretion model of chemical evolution are compared to the observations of the stellar masses and metallicities of star-forming galaxies. With the addition of one parameter, the model can account for 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…
In order to recognize environmental effects on the evolution of dwarf galaxies in clusters of galaxies, it is first necessary to quantify the properties of objects which have evolved in relative isolation. With oxygen abundance as the gauge…
The primary present-day observables upon which theories of galaxy evolution are based are a system's morphology, dynamics, colour, and chemistry. Individually, each provides an important constraint to any given model; in concert, the four…
Standard models for the chemical evolution of the Galaxy are reviewed with particular emphasis on the history of the abundance gradients in the disk. The effects on the disk structure and metallicity of gas accretion are discussed, showing…
The first part of this paper deals with the impact of nonsolar and - for late-type, dwarf, and high redshift galaxies - generally subsolar abundances on the interpretation of observational data for starburst galaxies. It points out the…
The horizon for studies of element abundances has expanded dramatically in the last ten years. Once the domain of astronomers concerned chiefly with stars and nearby galaxies, this field has now become a key component of observational…
Planetary nebulae are the products of the evolution of low and intermediate mass stars. The chemical property studies of these objects give important information about the elemental abundances as He, O, Ne, Ar, S and their modifications…
This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abundances and plasma diagnostics were derived from selected…