English
Related papers

Related papers: The Earliest Phases of Galaxy Evolution

200 papers

The manner the galaxy accretes matter along with the star formation rates at different epochs, influence the evolution of the stable isotopic inventories of the galaxy. A detailed analysis is presented here to study the dependence of the…

Astrophysics of Galaxies · Physics 2014-08-05 S. Sahijpal

We discuss the evolution of oxygen, carbon and nitrogen in galaxies of different morphological type by adopting detailed chemical evolution models with different star formation histories (continuous star formation or starbursts). We start…

Astrophysics · Physics 2009-11-07 Cristina Chiappini , Donatella Romano , Francesca Matteucci

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

Inhomogeneous chemical evolution models of galaxies which try to reproduce the scatter seen in element-to-iron ratios of metal-poor halo stars are heavily dependent on theoretical nucleosynthesis yields of core-collapse supernovae. Hence…

Astrophysics · Physics 2009-11-06 D. Argast , M. Samland , F. -K. Thielemann , O. E. Gerhard

The mean alpha-to-iron abundance ratio ([$\alpha$/Fe]) of galaxies is sensitive to the chemical evolution processes at early time, and it is an indicator of star formation timescale ($\tau_{{\rm SF}}$). Although the physical reason remains…

Astrophysics of Galaxies · Physics 2016-10-05 Yiqing Liu , Luis C. Ho , Eric Peng

The proto-Milky Way epoch forms the earliest stars in our Galaxy and sets the initial conditions for subsequent disk formation. Recent observations from APOGEE and H3 surveys showed that the [$\alpha$/Fe] ratio slowly declined between…

Astrophysics of Galaxies · Physics 2024-11-11 Boquan Chen , Yuan-Sen Ting , Michael Hayden

In this work we explore the effects of adopting initial mass functions (IMFs) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the…

Astrophysics · Physics 2009-10-31 Cristina Chiappini , Francesca Matteucci , Paolo Padoan

We present a theoretical method for solving the chemical evolution of galaxies, by assuming an instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed…

Astrophysics of Galaxies · Physics 2017-01-18 Fiorenzo Vincenzo , Francesca Matteucci , Emanuele Spitoni

Since stellar populations enhance particular element abundances according to the yields and lifetimes of the stellar progenitors, the chemical evolution of galaxies serves as one of the key tools that allows the tracing of galaxy evolution.…

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

We have investigated the poorly-understood origin of nitrogen in the early Galaxy by determining N abundances in 35 extremely metal-poor halo giants (22 stars have [Fe/H]<-3.0) using the C and O abundances determined in Paper V. Because any…

Recent stellar chemical abundance measurements of a handful of $z\sim2$ quiescent galaxies have suggested these galaxies exhibit a remarkably strong $\alpha$-enhancement compared to their local and intermediate redshift counterparts. This…

Astrophysics of Galaxies · Physics 2025-06-27 Marziye Jafariyazani , Andrew B. Newman , Bahram Mobasher , Sirio Belli , Richard S. Ellis , Andreas L. Faisst

A model for Galactic chemical evolution, driven by supernova-induced star formation, is formulated and used to examine the nature of the Galactic halo at early epochs. In this model, new stars are formed following each supernova event, thus…

Astrophysics · Physics 2009-10-31 Takuji Tsujimoto , Toshikazu Shigeyama , Yuzuru Yoshii

In the framework of an ESO Large Programme high quality spectra of 70 very metal-poor dwarfs and giants were obtained with the VLT-UVES combination. This paper reports the detailed analyses of the 35 giants of the sample. At the exception…

An attempt is made, probably for the first time, to understand the origin of the solar system in context with the evolution of the galaxy as a natural consequence of the birth of several generations of stellar clusters. The galaxy is…

Solar and Stellar Astrophysics · Physics 2014-06-10 Sandeep Sahijpal

We present results on carbon, nitrogen, and oxygen abundances for a sample of unevolved metal-poor stars with metallicities in the range -0.3< [Fe/H]< -3. Oxygen abundances derived from different indicators are compared showing consistently…

Astrophysics · Physics 2016-01-27 G. Israelian , R. Garcia Lopez , Rafael Rebolo

We present models for the evolution of the elemental abundances in the gas and dust phases of the interstellar medium (ISM) of our Galaxy by generalizing standard models for its dynamical and chemical evolution. In these models, the stellar…

Astrophysics · Physics 2009-10-30 Eli Dwek

Dramatic recent progress in understanding galactic chemical evolution (GCE) has been driven partly by direct observations of the distant past with HST and JWST of stellar abundances from giant high-resolution spectroscopic surveys (APOGEE,…

Astrophysics of Galaxies · Physics 2025-02-19 David H. Weinberg

We have extended our analytical chemical evolution modelling ideas for the Galaxy to the Magellanic Clouds. Unlike previous authors, we assume neither a steepened IMF nor selective galactic winds, since among the alpha-particle elements…

Astrophysics · Physics 2009-07-28 B. E. J. Pagel , G. Tautvaisiene

The spatial distribution of elemental abundances in the disc of our Galaxy gives insights both on its assembly process and subsequent evolution, and on the stellar nucleogenesis of the different elements. Gradients can be traced using…

Recent improvements in the age dating of stellar populations and single stars allow us to study the ages and abundance of stars and galaxies with unprecedented accuracy. We here compare the relation between age and \alpha-element abundances…

Astrophysics of Galaxies · Physics 2016-10-19 C. J. Walcher , R. M. Yates , I. Minchev , C. Chiappini , M. Bergemann , G. Bruzual , S. Charlot , P. R. T. Coelho , A. Gallazzi , M. Martig