Influence of Inelastic Collisions with Hydrogen Atoms on Non-LTE Oxygen Abundance Determination in the Sun and late-type stars

Abstract

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The non-LTE abundances from the O I lines were determined for the Sun and 46 FG stars in a wide metallicity range, -2.6 < [Fe/H] < 0.2. An application of accurate atomic data leads to larger departures from LTE and lower oxygen abundances compared to that for the Drawin's theoretical approximation. For the infrared O I 7771-5 A triplet lines, the change in the non-LTE abundance is -0.11 dex for the solar atmospheric parameters and decreases in absolute value towards lower metallicity. We revised the [O/Fe]-[Fe/H] trend derived in our earlier study. The change in [O/Fe] is small in the [Fe/H] range from -1.5 to 0.2. For stars with [Fe/H] < -1, the [O/Fe] ratio has increased such that [O/Fe] = 0.60 at [Fe/H] = -0.8 and increases up to [O/Fe] = 0.75 at [Fe/H] = -2.6.

arXiv commentPublished in Astronomy Letters

References in corpus (38)

• Validation of the new Hipparcos reduction
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• Towards Better Age Estimates for Stellar Populations: The Y^2 Isochrones for Solar Mixture
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• Line formation in solar granulation: IV. [O I], OI and OH lines and the photospheric O abundance
• An absolutely calibrated effective temperature scale from the InfraRed Flux Method
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• The photospheric solar oxygen project: I. Abundance analysis of atomic lines and influence of atmospheric models
• A non-LTE study of neutral and singly-ionized iron line spectra in 1D models of the Sun and selected late-type stars
• Oxygen Abundances in Nearby FGK Stars and the Galactic Chemical Evolution of the Local Disk and Halo
• Stellar Diameters and Temperatures III. Main Sequence A, F, G, & K Stars: Additional high-precision measurements and empirical relations
• Oxygen abundances in unevolved metal-poor stars from near-UV OH lines
• O/Fe in metal-poor main sequence and subgiant stars
• Stellar Diameters and Temperatures I. Main Sequence A, F, & G 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
• Experimental f-value and isotopic structure for the Ni I line blended with [OI] at 6300A
• Stellar Diameters and Temperatures V. Eleven Newly Characterized Exoplanet Host Stars
• Center-to-Limb Variation of Solar Line Profiles as a Test of NLTE Line Formation Calculations
• How do Uncertainties in the Surface Chemical Abundances of the Sun Affect the Predicted Solar Neutrino Fluxes?
• Systematic NLTE study of the -2.6 < [Fe/H] < 0.2 F and G dwarfs in the solar neighbourhood. I. Stellar atmosphere parameters
• Excitation and charge transfer in low-energy hydrogen atom collisions with neutral atoms: Theory, comparisons, and application to Ca
• Neutral oxygen spectral line formation revisited with new collisional data: large departures from LTE at low metallicity
• Oxygen lines in solar granulation. II. Centre-to-limb variation, NLTE line formation, blends and the solar oxygen abundance
• Inelastic Na+H collision data for non-LTE applications in stellar atmospheres
• Inelastic Mg+H collision data for non-LTE applications in stellar atmospheres
• Fundamental properties of the Population II fiducial stars HD 122563 and Gmb 1830 from CHARA interferometric observations
• Electron-impact excitation of neutral oxygen
• Oxygen Abundances in Metal-Poor Stars
• The Galactic chemical evolution of oxygen inferred from 3D non-LTE spectral line formation calculations
• Benchmark stars for Gaia: fundamental properties of the Population II star HD140283 from interferometric, spectroscopic and photometric data
• Accuracy of atmospheric parameters of FGK dwarfs determined by spectrum fitting
• Accurate effective temperatures of the metal-poor benchmark stars HD 140283, HD 122563 and HD 103095 from CHARA interferometry
• Cosmic variance in [O/Fe] in the Galactic disk
• The radius and other fundamental parameters of the F9 V star beta Virginis
• Excitation and charge transfer in low-energy hydrogen atom collisions with neutral oxygen

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