Search for Extremely Metal-poor Stars with Gemini-N/Graces. I. Chemical-abundance Analysis
The Astrophysical Journal, 2023 We present stellar parameters and abundances of 13 elements for 18 very metal-poor (VMP; [Fe/H] < –2.0) stars, selected as extremely metal-poor (EMP; [Fe/H] < –3.0) candidates from the Sloan Digital Sky Survey and Large sky Area Multi-Object Fiber ...
Miji Jeong +7 more
doaj +1 more source
Chemical abundances and radial velocities in the extremely metal-poor galaxy DDO 68 [PDF]
Monthly notices of the Royal Astronomical Society, 2018 We present chemical abundances and radial velocities of six HII regions in the extremely metal-poor star-forming dwarf galaxy DDO 68. They are derived from deep spectra in the wavelength range 3500 - 10,000 {\AA}, acquired with the Multi Object Double ...
F. Annibali +20 more
semanticscholar +1 more source
Analysis of chemical abundances in planetary nebulae with [WC] central stars [PDF]
Astronomy & Astrophysics, 2013 Accepted for publication in A&A. 15 Tables and 18 Figures.
Maria Teresa Ruiz +7 more
openaire +5 more sources
Chemical abundances in Seyfert galaxies – X. Sulphur abundance estimates
Monthly Notices of the Royal Astronomical Society, 2023 ABSTRACT For the first time, the sulphur abundance relative to hydrogen (S/H) in the narrow-line regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission-line intensities from the Sloan Digital Sky Survey (SDSS) Data Release 17 (DR17) [in the wavelength range 3000
Oli L Dors +14 more
openaire +3 more sources
High-resolution Chemical Abundances of the Nyx Stream
The Astrophysical Journal, 2023 Nyx is a nearby, prograde, and high-eccentricity stellar stream physically contained in the thick disk, but its origin is unknown. Nyx could be the remnant of a disrupted dwarf galaxy, in which case the associated dark matter substructure could affect ...
Shuyu Wang +7 more
doaj +1 more source
Chemical Abundances of New Member Stars in the Tucana II Dwarf Galaxy [PDF]
, 2018 We present chemical abundance measurements for seven stars with metallicities ranging from Fe/H] = −3.3 to [Fe/H] = −2.4 in the Tucana II ultra-faint dwarf galaxy (UFD), based on high-resolution spectra obtained with the MIKE spectrograph on the 6.5 m ...
A. Chiti +5 more
semanticscholar +1 more source
The R-Process Alliance: Chemical Abundances for a Trio of r-process-enhanced Stars—One Strong, One Moderate, and One Mild [PDF]
Astrophysical Journal, 2018 We present detailed chemical abundances of three new bright (V ∼ 11), extremely metal-poor ([Fe/H] ∼ −3.0), r-process-enhanced halo red giants based on high-resolution, high-S/N Magellan/MIKE spectra.
M. Cain +11 more
semanticscholar +1 more source
Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program. II. Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu [PDF]
, 2017 To understand the formation and evolution of the different stellar populations within our Galaxy it is essential to combine detailed kinematical and chemical information for large samples of stars.
E. D. Mena +6 more
semanticscholar +1 more source
How Efficient is Rotational Mixing in Massive Stars ? [PDF]
, 2007 The VLT-Flames Survey for Massive Stars (Evans05,Evans06) provides recise measurements of rotational velocities and nitrogen surface abundances of massive stars in the Magellanic Clouds.
Anders, P. +3 more
core +6 more sources
Chemical Abundances in our Galaxy and Other Galaxies Derived from H II Regions [PDF]
Astrophys.Space Sci. 277 (2001) 147-156, 2000 We discuss the accuracy of the abundance determinations of H II regions in our Galaxy and other galaxies. We focus on the main observational constraints derived from abundance determinations that have implications for models of galactic chemical evolution: a) the helium to hydrogen abundance ratio, He/H; b) the oxygen to hydrogen abundance ratio, O/H ...
arxiv +1 more source