Related papers: High-precision stellar abundances of the elements …
Chemical tagging is a central pursuit of galactic archaeology, but requires sufficiently discriminative abundances to uniquely identify sites of star formation. This task is complicated by intrinsic scatter among conatal stars,…
The ability to measure metallicities and {\alpha}-element abundances in individual red giant branch (RGB) stars using medium-resolution spectra ($R \approx 6000$) is a valuable tool for deciphering the nature of Milky Way dwarf satellites…
We present preliminary results of a detailed chemical abundance analysis for a sample of solar-type stars known to exhibit excess infrared emission associated with dusty debris disks. Our sample of 28 stars was selected based on results…
The determination of the heavy element abundances from giant extragalactic H II regions is based on collisionally excited lines. We argue that in the presence of temperature variations the abundances determined are lower limits to the real…
Understanding stellar composition is fundamental not only to our comprehension of the galaxy, especially chemical evolution, but it can also shed light on the interior structure and mineralogy of exoplanets, which are formed from the same…
Accurate determination of stellar atmospheric parameters and elemental abundances is crucial for Galactic archeology via large-scale spectroscopic surveys. In this paper, we estimate stellar atmospheric parameters -- effective temperature…
Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C,…
Differential abundances of C, O, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, and Zr were determined from high signal-to-noise VLT/UVES spectra for 25 turnoff stars with -2.4 < [Fe/H] < -1.3. Effective temperatures were obtained from…
I present here the main results of recent realistic, 3D, hydrodynamical simulations of convection at the surface of metal-poor red giant stars. I discuss the application of these convection simulations as time-dependent, 3D, hydrodynamical…
Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding its…
In this review we present a brief discussion on the observational evidence in favor of the presence of temperature variations, and conclude that many planetary nebulae show spatial temperature variations that are larger than those predicted…
Results from high-resolution spectral analyses of a selected sample of CH stars are presented. Detailed chemical composition studies of these objects, which could reveal abundance patterns that in turn provide information regarding…
Metal-poor M subdwarfs are among the oldest stellar populations and carry valuable information about the chemical enrichment history of the Milky Way. The measurements of chemical abundances of these stars therefore provide essential…
We present a high-precision differential abundance analysis of 16 solar-type stars in the Hyades open cluster based on high resolution, high signal-to-noise ratio (S/N ~ 350 - 400) spectra obtained from the McDonald 2.7m telescope. We…
Precise abundance ratios are determined for 94 dwarf stars with 5200 < Teff < 6300 K, -1.6 < [Fe/H] < -0.4, and distances D < 335 pc. Most of them have halo kinematics, but 16 thick-disk stars are included. Equivalent widths of atomic lines…
We measure abundances of 12 elements (Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni) in a sample of 86 metal-poor ($-2 \lesssim \text{[Fe/H]} \lesssim -1$) subgiant stars in the solar neighborhood. Abundances are derived from…
Large-scale surveys will provide spectroscopy for $\sim$50 million resolved stars in the Milky Way and Local Group. However, these data will have a high degree of heterogeneity and most will be low-resolution ($R<10000$), posing challenges…
We discuss the way of increasing of the number of chemical elements, investigated in stellar spectra. We can reach it by using spectrum synthesis method, new atomic data and observation of stellar spectra with resolution comparable to solar…
Helium abundances and atmospheric parameters have been determined from high resolution spectra for a new sample of 46 bright hot subdwarf B (sdB) stars. The helium abundances have been measured with high accuracy. We confirm the correlation…
We present the first results of an extensive spectroscopic survey of directly imaged planet host stars. The goal of the survey is the measurement of stellar properties and abundances of 15 elements (including C, O, and S) in these stars. In…