Results 211 to 220 of about 59,640 (247)

Chemical and Dynamical Evolution of Spiral Galaxies

Astrophysics and Space Science, 2002
We present the very first results of a new 3D numerical model for the formation and evolution of spiral galaxies along the Hubble sequence. We take into account the hydrodynamical properties of the gas with an SPH method while we use a tree code for the gravitational forces of the dark matter and stars.
Poirier, Sébastien, Jablonka, Pascale, Alimi, Jean-Michel   +2 more
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The chemical evolution of galaxies

Vistas in Astronomy, 1975
Abstract Emphasis is placed on the simplest models of the chemical evolution of galaxies, and the role played by the concentration of the interstellar gas to gravitational stable regions is taken into account. Although Schmidt's simple model is improved when concentration is allowed for, it still predicts too wide a spread of metal abundances for ...
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Inhomogeneous chemical evolution of dwarf spheroidal galaxies

Astrophysics and Space Science, 2003
Stellar abundance pattern of n-capture elements such as barium is used as a powerful tool to infer how the star formation proceeded in dwarf spheroidal (dSph) galaxies. It is found that the abundance correlation of barium with iron in stars belonging to dSph galaxies orbiting the Milky Way, i.e., Draco, Sextans, and Ursa Minor have a feature similar to
Takuji Tsujimoto, Toshikazu Shigeyama
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Chemical evolution in simulations of galaxy formation

Astrophysics and Space Science, 2002
We developed a new algorithm to implement detailed chemical evolution in SPH models of galaxy formation. Delayed gas restitution and different production timescales for different elements are taken into account, with minor computational effort. The algorithm is especially conceived for SPH simulations with large numbers of particles, and for parallel ...
Portinari,L, CARRARO, GIOVANNI, Lia,C
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Chemical Abundances and Galaxy Evolution

1984
The chemical abundance characteristics of two comparatively structurally simple classes of galaxies, the ellipticals and irregulars, are briefly reviewed. Neither of these types of galaxies have properties which are fully consistent with the quantitative predictions of basic chemical evolution models. Possible sources for discrepancies are discussed in
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Chemical and photometric evolution of elliptical galaxies

Space Science Reviews, 1994
In this paper we present the new chemical-spectro-photometric models of population synthesis by Bressan, Chiosi & Fagotto (1993). The models are specifically designed for elliptical galaxies. They include the presence of dark matter and galactic winds triggered by the energy depositfrom supernovae and winds of massive stars.
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Chemical evolution of two-component galaxies

Astrophysics and Space Science, 1978
Results provided by analytical models for the chemical evolution of two-component (spheroidal and disk) galaxies based on the instantaneous recycling approximation are compared with numerical results obtained by discarding the cited approximation. The assumptions and general equations used in the calculations are discussed, and the method adopted for ...
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Chemical Evolution of Irregular Galaxies

2011
In this chapter, we describe the properties of irregular galaxies and the proposed chemical evolution models. Irregular galaxies are generally small and rather simple objects with low metallicity and large gas content, suggesting that they are either young objects or have undergone discontinuous star formation activity (bursts) or a continuous but not ...
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Cosmic chemical evolution and the evolution of galaxies

AIP Conference Proceedings, 2000
The evolutionary history of star and element formation rates with cosmic epoch is reviewed. The problem of taking proper account of the effects of dust obscuration in optical and ultraviolet observations is emphasised. Recent submillimetre surveys have been used to derive the star formation rate as a function of cosmic epoch independent of dust ...
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A repeating fast radio burst source localized to a nearby spiral galaxy

Nature, 2020
Benito Marcote, Kenzie Nimmo, Jason Hessels   +2 more
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