相关论文: Evidence of Early Enrichment of the Galactic Disk …
We adopt a scenario in which the Galactic thick disk was formed by minor merging between the first generation of the Galactic thin disk (FGTD) and a dwarf galaxy about 9 Gyr ago and thereby investigate chemical and dynamical properties of…
Elliptical galaxies are often assumed to be the primary source of heavy elements in the intracluster medium (ICM), with the contribution of other morphological types being negligible. In this paper we argue that a role of spiral galaxies in…
We present the results of our investigation of three samples kinematically representative of the thin and thick disks and the Hercules stream using the catalogue of Soubiran & Girard (2005). We have observed abundance trends and age…
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…
The role of planetary nebulae as probes for the galactic chemical evolution is reviewed. Their abundances throughout the Galaxy are discussed for key elements, in particular oxygen and other alpha elements. The abundance distribution…
We study the evolution of nitrogen in the Galactic halo, thick disc, thin disc and bulge by comparing detailed chemical evolution models with recent observations. The models used in this work have already been constrained to explain the…
We present a scenario of the chemical enrichment of the solar neighborhood that solves the G-dwarf problem by taking into account constraints on a larger scale. We argue that the Milky Way disk within 10 kpc has been enriched to solar…
We analyse the evolution of the oxygen abundance gradient of star-forming galaxies with stellar mass Mstar > 10^9 Mo in the EAGK simulation over the redshift range z=[0, 2.5]. We find that the median metallicity gradient of the simulated…
In this letter we examine the evolution of the radial metallicity gradient induced by secular processes, in the disk of an $N$-body Milky Way-like galaxy. We assign a [Fe/H] value to each particle of the simulation according to an initial,…
We show that the Galactic bulge and disk share a similar, strong, decline in [O/Mg] ratio with [Mg/H]. The similarity of the [O/Mg] trend in these two, markedly different, populations suggests a metallicity-dependent modulation of the…
We use recent observations of high-redshift galaxies to study the evolution of galactic disks over the redshift range 0<z<1. The data are inconsistent with models in which disks were already assembled at z=1 and have evolved only in…
We present a multi-zone galactic chemical evolution (GCE) model for the Milky Way that takes the most recently updated yields of major nucleosynthesis channels into account. It incorporates physical processes commonly found in previous GCE…
We investigate the evolution of galactic disks in N-body Tree-SPH simulations. We find that disks, initially truncated at three scale-lengths, can triple their radial extent, solely driven by secular evolution. Both Type I (single…
We develop a hybrid model of galactic chemical evolution that combines a multi-ring computation of chemical enrichment with a prescription for stellar migration and the vertical distribution of stellar populations informed by a cosmological…
Disc galaxies show a large morphological diversity with varying contribution of three major structural components; thin discs, thick discs, and central bulges. Dominance of bulges increases with the galaxy mass (Hubble sequence) whereas…
We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be 18, Be 21, Be 22, Be 32, and PWM 4. For Be 18 and PWM 4, these are the first chemical abundance measurements. Combining our data with…
Models of the chemical evolution of our Galaxy are extended to include radial migration of stars and flow of gas through the disc. The models track the production of both iron and alpha elements. A model is chosen that provides an excellent…
Carbon abundances in first-ascent giant stars are usually lower than those of their main-sequence counterparts. At moderate metallicities, stellar evolution of single stars cannot account for the existence of red-giant branch stars with…
The distribution of gas-phase abundances in galaxy disks encodes the history of nucleosynthesis and transport through the interstellar medium (ISM) over cosmic time. Multi-object and high resolution integral-field spectroscopy have started…
The space velocities and Galactic orbital elements of stars calculated from the currently available high-accuracy observations in our summary catalog of spectroscopic magnesium abundances in dwarfs and subgiants in the solar neighborhood…