Non-LTE abundances of Mg and K in extremely metal-poor stars and the evolution of [O/Mg], [Na/Mg], [Al/Mg] and [K/Mg] in the Milky Way

Abstract

LTE abundances of light elements in extremely metal-poor (EMP) stars have been previously derived from high quality spectra. New derivations, free from the NLTE effects, will better constrain the models of the Galactic chemical evolution and the yields of the very first supernovae. The NLTE profiles of the magnesium and potassium lines have been computed in a sample of 53 extremely metal-poor stars with a modified version of the program MULTI and adjusted to the observed lines in order to derive the abundances of these elements. The NLTE corrections for magnesium and potassium are in good agreement with the works found in the literature. The abundances are slightly changed, reaching a better precision: the scatter around the mean of the abundance ratios has decreased. Magnesium may be used with confidence as reference element. Together with previously determined NLTE abundances of sodium and aluminum, the new ratios are displayed, for comparison, along the theoretical trends proposed by some models of the chemical evolution of the Galaxy, using different models of supernovae.

Cited by in corpus (83)

• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• Quantifying the uncertainties of chemical evolution studies. II. Stellar yields
• An extremely primitive halo star
• Chemodynamical Simulations of the Milky Way Galaxy
• The s-Process in Low Metallicity Stars. II. Interpretation of High-Resolution Spectroscopic Observations with AGB models
• The elemental composition of the Sun I. The intermediate mass elements Na to Ca
• Normal and Outlying Populations of the Milky Way Stellar Halo at [Fe/H] < -2
• High-Resolution Spectroscopy of Extremely Metal-Poor Stars from SDSS/SEGUE: I. Atmospheric Parameters and Chemical Compositions
• Pre-galactic metal enrichment - The chemical signatures of the first stars
• Systematic non-LTE study of the $-2.6\le$ [Fe/H] $\le 0.2$ F and G dwarfs in the solar neighbourhood. II. Abundance patterns from Li to Eu
• News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419
• Abundance Profiling of Extremely Metal-Poor Stars and Supernova Properties in the Early Universe
• JINAbase: A database for chemical abundances of metal-poor stars
• The Bizarre Chemical Inventory of NGC 2419, An Extreme Outer Halo Globular Cluster
• Triangulum II: Not Especially Dense After All
• Chemical Abundances in the Ultra-Faint Dwarf Galaxies Grus I and Triangulum II: Neutron-Capture Elements as a Defining Feature of the Faintest Dwarfs
• The extremely low-metallicity tail of the Sculptor dwarf spheroidal galaxy
• The Chemical Abundances of Stars in the Halo (CASH) Project. II. A Sample of 16 Extremely Metal-poor Stars
• Principal Component Analysis on Chemical Abundances Spaces
• Tracing the evolution of NGC6397 through the chemical composition of its stellar populations
• The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal
• The Hamburg/ESO R-process Enhanced Star survey (HERES) X. HE 2252-4225, one more r-process enhanced and actinide-boost halo star
• High-resolution abundance analysis of very metal-poor r-I stars
• Chemical Analysis of the Ninth Magnitude Carbon-Enhanced Metal-Poor Star BD+44 493
• Experimental and theoretical oscillator strengths of Mg I for accurate abundance analysis
• The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis. II. Early chemical enrichment
• Metal-poor stars towards the Galactic bulge - a population potpourri
• Fundamental properties of the Population II fiducial stars HD 122563 and Gmb 1830 from CHARA interferometric observations
• Reviving old controversies: is the early Galaxy flat or round? Investigations into the early phases of the Milky Way formation through stellar kinematics and chemical abundances
• Non-LTE analysis of K I in late-type stars
• Zero-metallicity hypernova uncovered by an ultra metal-poor star in the Sculptor dwarf spheroidal galaxy
• Constraining cosmic scatter in the Galactic halo through a differential analysis of metal-poor stars
• The Peculiar Chemical Inventory of NGC 2419 -- An Extreme Outer Halo "Globular Cluster"
• A grid of NLTE corrections for magnesium and calcium in late-type giant and supergiant stars: application to Gaia
• NLTE determination of the calcium abundance and 3D corrections in extremely metal-poor stars
• Chemistry of the Most Metal-poor Stars in the Bulge and the z > 10 Universe
• First stars XIII. Two extremely metal-poor RR Lyrae stars?
• A critical reassessment of the fundamental properties of GJ 504: Chemical composition and age
• Computational issues in chemo-dynamical modelling of the formation and evolution of galaxies
• First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars
• NLTE line formation for Mg\ione\ and Mg\ii\ in atmospheres of B-A-F-G-K stars
• The value-added catalogue for LAMOST DR8 low-resolution spectra
• The occurrence of nitrogen-enhanced metal-poor stars: implications for the initial mass function in the early Galactic halo
• An abundance study of red-giant-branch stars in the Hercules dwarf spheroidal galaxy
• Non-LTE abundance corrections for late-type stars from 2000Å to 3μm: I. Na, Mg, and Al
• Potassium in globular cluster stars: comparing normal clusters to the peculiar cluster NGC 2419
• Gemini/GRACES Spectroscopy of Stars in Triangulum II
• Influence of departures from LTE on calcium, titanium, and iron abundance determinations in cool giants of different metallicities
• The origin of low [alpha/Fe] ratios in extremely metal-poor stars
• The Cosmic Hunt for Members in the Outskirts of Ultra Faint Dwarf Galaxies: Ursa Major I, Coma Berenices, and Boötes I
• X-Shooter GTO: Chemical analysis of a sample of EMP candidates
• Elemental Abundances in the Possible Type Ia Supernova Remnant G344.7-0.1
• High-resolution abundance analysis of HD 140283
• The Hamburg/ESO R-process Enhanced Star survey (HERES) VIII. The r+s star HE 1405 0822
• Neutron-capture elements in dwarf galaxies II: Challenges for the s- and i-processes at low metallicity
• Copper abundance from Cu I and Cu II lines in metal-poor star spectra: NLTE vs LTE
• A bound on the 12C/13C ratio in near-pristine gas with ESPRESSO
• Sulphur in the Sculptor dwarf spheroidal galaxy - Including NLTE corrections
• Abundances of Na, Mg, and K in the atmospheres of red giant branch stars of Galactic globular cluster 47 Tucanae
• Evidence of First Stars-enriched Gas in High-redshift Absorbers
• The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon
• A differential chemical element analysis of the metal poor Globular Cluster NGC 6397
• Pre-supernova mixing in CEMP-no source stars
• Systematic investigation of chemical abundances derived using IR spectra obtained with GIANO
• PISN-explorer: hunting the descendants of very massive first stars
• Sulphur abundances in halo stars from Multiplet 3 at 1045 nm
• Abundance analysis of SDSS J134338.67+484426.6; an extremely metal-poor star from the MARVELS pre-survey
• NLTE Analysis of High Resolution H-band Spectra. II. Neutral Magnesium
• Homogeneity in the early chemical evolution of the Sextans dwarf Spheroidal galaxy
• Inferring the velocity of early massive stars from the abundances of extremely metal-poor stars
• The stochastic enrichment of Population II stars
• Abundances of the light elements from UV (HST) and red (ESO) spectra in the very old star HD 84937
• Checking Potassium origin of new emission line at 3.5 keV with K XIX line complex at 3.7 keV
• Study of the departures from LTE in the unevolved stars infra-red spectra
• GalCEM I -- An Open-Source Detailed Isotopic Chemical Evolution Code
• Clues on the Galactic evolution of sulphur from star clusters
• Sulphur in the metal poor globular cluster NGC 6397
• Extremely Metal-Poor Stars and a Hierarchical Chemical Evolution Model
• Optical and NIR spectroscopy of cool CEMP stars to probe the nucleosynthesis in low mass AGB binary system
• Chemical abundances of the metal-poor horizontal-branch stars CS 22186-005 and CS 30344-033
• Unveiling the nature of HE 0107-5240
• Abundances of Mg and K in the atmospheres of turn-off stars in Galactic globular cluster 47 Tucanae
• The metal-poorest tail of the Galactic halo: hypothesis on its origin from precise spectral analysis