Related papers: The Chemical Evolution of Iron-Peak Elements with …
For the first time, we present an extensive study of stars with individual non-local thermodynamic equilibrium (NLTE) abundances for 17 chemical elements from Li to Eu in a sample of stars uniformly distributed over the $-2.62 \le$ [Fe/H]…
In this work we present chemical abundances of heavy elements (Z$>$28) for a homogeneous sample of 1059 stars from HARPS planet search program. We also derive ages using parallaxes from Hipparcos and Gaia DR1 to compare the results. We…
For the origin of heavy r-process elements, different sources have been proposed, e.g., core-collapse supernovae or neutron star mergers. Old metal-poor stars carry the signature of the astrophysical source(s). Among the elements dominantly…
We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni and Ba for 43 metal-poor field stars in the solar neighbourhood with iron abundances [Fe/H] ranging from -0.4 to -3.0. Total abundance errors are estimated to about…
We examine the contribution of electron-capture supernovae (ECSNe), low-mass SNe from collapsing Fe cores (FeCCSNe), and rotating massive stars to the chemical composition of the Galaxy. Our model includes contributions to chemical…
Understanding the chemical enrichment of different elements is crucial to gaining a complete picture of galaxy chemical evolution. In this study, we present a new sample of 46 low-redshift, low-mass star-forming galaxies at $M_*\sim…
An early history of metal enrichment in the Galactic halo is studied. We investigate chemical inhomogeneity by using a stochastic chemical evolution model. The model confronts with metallicity distribution function of long-lived halo stars…
Elements heavier than hydrogen and helium, collectively termed metals, were created inside stars and dispersed through space at the final stages of stellar evolution. The relative amounts of different isotopes (variants of the same element…
The unique elemental abundance pattern of the carbon-rich stars CS29498-043 and CS22949-037 is characterized by a large excess of magnesium and silicon in comparison with iron. This excess is investigated in the context of a…
Due to their different nucleosynthetic origin, a stellar population produces oxygen (O) and iron (Fe) on different timescales and their relative abundance can deviate strongly from solar. Galaxy formation models should treat these elements…
We provide new nucleosynthesis yields depending on metallicity and energy (i.e., (normal supernovae and hypernovae), and show the evolution of heavy element abundances from C to Zn in the solar neighborhood. We then show the chemodynamical…
We present a novel approach aimed at identifying the key chemical elements to search for the (missing) descendants of very massive first stars exploding as Pair Instability Supernovae (PISN). Our simple and general method consists in a…
We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The analyses of carbon-enhanced stars in our…
Aims. The Chemical Evolution of R-process Elements in Stars (CERES) project aims to provide a homogeneous analysis of a sample of metal-poor stars ([Fe/H]<-1.5). We present the stellar parameters and the chemical abundances of elements up…
We have developed a detailed standard chemical evolution model to study the evolution of all the chemical elements up to the iron peak in the solar vicinity. We consider that the Galaxy was formed through two episodes of exponentially…
We extend our model of chemical evolution that successfully account for the main observables in the solar neighborhood (Alibes, Labay & Canal 2001) to the whole Milky Way halo and disk. We assume an inside-out scenario for the assembling of…
Recent work presented increasing evidence of high, non-constant S/O abundance ratios observed in star-forming metal-poor galaxies, showing deviations from the constant canonical S/O across a large range of O/H abundance. Similar peculiar…
We present a comprehensive study of the abundance evolution of the elements from H to U in the Milky Way halo and local disk. We use a consistent chemical evolution model, metallicity dependent isotopic yields from low and intermediate mass…
We present the elemental abundances and ages of 19 massive quiescent galaxies at $z\sim1.4$ and $z\sim2.1$ from the Keck Heavy Metal Survey. The ultra-deep LRIS and MOSFIRE spectra were modeled using a full-spectrum stellar population…
After the Big Bang nucleosynthesis, the first heavy element enrichment in the Universe was made by a supernova (SN) explosion of a population (Pop) III star (Pop III SN). The abundance ratios of elements produced from Pop III SNe are…