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Related papers: Early Star Formation and Chemical Evolution in Pro…

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We present a general phenomenological model for the metallicity distribution (MD) in terms of [Fe/H] for dwarf spheroidal galaxies (dSphs). These galaxies appear to have stopped accreting gas from the intergalactic medium and are fossilized…

Astrophysics of Galaxies · Physics 2015-06-04 Yong-Zhong Qian , Gerald J. Wasserburg

We investigate chemical evolution in Milky Way-like galaxies based on the cold dark matter model in which cosmic structures form via hierarchical merging. We introduce chemical enrichment due to type Ia supernovae (SNe Ia) into the Mitaka…

Astrophysics · Physics 2009-11-10 Masahiro Nagashima , Takashi Okamoto

We investigate the metallicity distribution function (MDF) in the Galactic halo and the relative fraction of Carbon-normal and Carbon-rich stars. To this aim, we use an improved version of the semi-analytical code GAlaxy MErger Tree and…

Astrophysics of Galaxies · Physics 2015-06-22 Matteo de Bennassuti , Raffaella Schneider , Rosa Valiante , Stefania Salvadori

The chemical enrichment of the early Universe is a crucial element in the formation and evolution of galaxies, and Population III (PopIII) stars must play a vital role in this process. In this study, we examine metal enrichment from massive…

Astrophysics of Galaxies · Physics 2024-02-07 Devesh Nandal , John A. Regan , Tyrone E. Woods , Eoin Farrell , Sylvia Ekström , Georges Meynet

Chemical abundances and abundance ratios measured in galaxies provide precious information about the mechanisms, modes and time scales of the assembly of cosmic structures. Yet, the nucleogenesis and chemical evolution of elements heavier…

Astrophysics of Galaxies · Physics 2019-12-04 Donatella Romano , Francesca Matteucci , Zhi-Yu Zhang , Rob J. Ivison , Paolo Ventura

The cosmic star formation histories are evaluated for different minimum masses of the initial halo structures, with allowance for realistic gas outflows. With a minimum halo mass of 10^{7} - 10^{8} M_odot and a moderate outflow efficiency,…

Astrophysics · Physics 2009-09-15 Frederic Daigne , Keith A. Olive , Joe Silk , Felix Stoehr , Elisabeth Vangioni

[abridged] The First Stars in the Universe form out of pristine primordial gas clouds that have been radiatively cooled to a few hundreds of degrees Kelvin either via molecular or atomic (Lyman-Alpha) hydrogen lines. This primordial mode of…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 M. Trenti , M. Stiavelli

We use detailed nucleosynthesis calculations and a realistic prescription for the environment of the first stars to explore the first episodes of chemical enrichment that occurred during the dark ages. Based on these calculations, we…

Astrophysics of Galaxies · Physics 2015-06-19 Ryan Cooke , Piero Madau

Observations of molecular clouds in metal-poor environments typically find that they have much higher star formation rates than one would expect based on their observed CO luminosities and the molecular gas masses that are inferred from…

Astrophysics of Galaxies · Physics 2015-06-04 Simon C. O. Glover , Paul C. Clark

Population III stars are believed to have been more massive than typical stars today and to have formed in relative isolation. The thermodynamic impact of metals is expected to induce a transition leading to clustered, low-mass Population…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Chalence Safranek-Shrader , Milos Milosavljevic , Volker Bromm

We perform a large set of radiation hydrodynamics simulations of primordial star formation in a fully cosmological context. Our statistical sample of 100 First Stars show that the first generation of stars have a wide mass distribution…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Shingo Hirano , Takashi Hosokawa , Naoki Yoshida , Hideyuki Umeda , Kazuyuki Omukai , Gen Chiaki , Harold W. Yorke

The metallicity distribution function (MDF) of the Galactic bulge features a multi-peak shape, with a metal-poor peak at [Fe/H]=-0.3 dex and a metal-rich peak at [Fe/H]=+0.3 dex. This bimodality is also seen in [alpha/Fe] versus [Fe/H]…

Astrophysics of Galaxies · Physics 2024-05-22 M. Molero , F. Matteucci , E. Spitoni , A. Rojas-Arriagada , R. M. Rich

All stellar evolution models for nucleosynthesis require an initial isotopic abundance set to use as a starting point. Generally, our knowledge of isotopic abundances of stars is fairly incomplete except for the Solar System. We present a…

Solar and Stellar Astrophysics · Physics 2015-06-04 Christopher West , Alexander Heger

We investigate the evolution of the metallicity of the intergalactic medium (IGM) with particular emphasis on its spatial distribution. We propose that metal enrichment occurs as a two step process. First, supernova (SN) explosions eject…

Astrophysics · Physics 2008-11-26 Andrea Ferrara , Max Pettini , Yuri Shchekinov

The theory for the formation of the first population of stars (Pop III) predicts a IMF composed predominantly of high-mass stars, in contrast to the present-day IMF, which tends to yield stars with masses less than 1 M_Solar. The leading…

Astrophysics of Galaxies · Physics 2015-05-27 Gustavo Dopcke , Simon C. O. Glover , Paul C. Clark , Ralf S. Klessen

(Abriged) We report results of a campaign to image the stellar populations in the halos of highly inclined spiral galaxies, with the fields roughly 10 kpc (projected) from the nuclei. We use the F814W (I) and F606W (V) filters in the Wide…

Astrophysics · Physics 2009-11-13 M. Mouhcine , R. M. Rich , H. C. Ferguson , T. M. Brown , T. E. Smith

We present chemical abundance analyses of sodium, iron-peak and neutron-capture elements for 97 kinematically selected thick disk, inner halo and outer halo stars with metallicities -3.3<[Fe/H]<-0.5. The main aim of this study is to examine…

Astrophysics of Galaxies · Physics 2015-06-16 Miho N. Ishigaki , Wako Aoki , Masashi Chiba

Because of their low gravitational energies dwarf galaxies are greatly exposed to energetical influences by the interstellar medium, like e.g.\ stellar radiation, winds or explosions, or by their environment. While the metallicity depletion…

Astrophysics · Physics 2007-05-23 G. Hensler , A. Rieschick

We present predictions of the evolution of the light elements, Li, Be, and B, in the early epochs of the Galactic halo, using a model of supernova-induced chemical evolution based on contributions from supernovae (SNe) and cosmic rays…

Astrophysics · Physics 2009-10-31 Takeru Ken Suzuki , Yuzuru Yoshii

We investigate early galaxy evolution by modeling self-consistently their radially-resolved evolution of gas, stars, heavy elements, and dust content. Our model successfully reproduces various observed properties of JWST-identified galaxies…

Astrophysics of Galaxies · Physics 2025-02-19 Daisuke Toyouchi , Hidenobu Yajima , Andrea Ferrara , Kentaro Nagamine
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