3D NLTE modelling of Y and Eu. Centre-to-limb variation and solar abundances

Abstract

Context. Abundances of s- and r-process elements in Sun-like stars constrain nucleosynthesis in extreme astrophysical events, such as compact binary mergers and explosions of highly magnetised rapidly rotating massive stars. Aims. We measure solar abundances of yttrium (Y) and europium (Eu) using 3D non-local thermal equilibrium (NLTE) models. We use the model to determine the abundance of Y, and also explore the model's ability to reproduce the solar centre-to-limb variation of its lines. In addition, we determine the Eu abundance using solar disc-centre and integrated flux spectra. Methods. We developed an NLTE model of Eu and updated our model of Y with collisional data from detailed quantum-mechanical calculations. We used the IAG spatially resolved high-resolution solar spectra to derive the solar abundances of Y across the solar disc and of Eu for integrated flux and at disc centre using a set of carefully selected lines and a 3D radiation-hydrodynamics model of the solar atmosphere. Results. We find 3D NLTE solar abundances of A(Y)${}_{\text{3D NLTE}}$=$2.30\pm 0.03_{\text{stat}}\pm 0.07_{\text{syst}}$ dex based on observations at all angles and A(Eu)${}_{\text{3D NLTE}}$=$0.57\pm 0.01_{\text{stat}}\pm 0.06_{\text{syst}}$ dex based on the integrated flux and disc-centre intensity. 3D NLTE modelling offers the most consistent abundances across the solar disc, and resolves the problem of severe systematic bias in Y and Eu abundances inherent to 1D LTE, 1D NLTE, and 3D LTE modelling.

8 pages, 4 figures, accepted by A&A

References in corpus (17)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The chemical make-up of the Sun: A 2020 vision
• Identification of strontium in the merger of two neutron stars
• Galactic Chemical Evolution and solar s-process abundances: dependence on the 13C-pocket structure
• The elemental composition of the Sun III. The heavy elements Cu to Th
• Atomic data for the Gaia-ESO Survey
• Non-LTE line formation for heavy elements in four very metal-poor stars
• Solar oxygen abundance
• Magnetorotational supernovae: A nucleosynthetic analysis of sophisticated 3D models
• Observational constraints on the origin of the elements II. 3D non-LTE formation of Ba ii lines in the solar atmosphere
• Low-mass low-metallicity AGB stars as an efficient i-process site explaining CEMP-rs stars
• Neutron-capture elements in the metal-poor globular cluster M15
• Observational constraints on the origin of the elements. VII. NLTE analysis of Y II lines in spectra of cool stars and implications for Y as a Galactic chemical clock
• The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres
• The IAG spectral atlas of the spatially resolved Sun: Centre-to-limb observations
• Solar oxygen abundance using SST/CRISP center-to-limb observations of the O I 7772 Å line
• Solar center-to-limb variation in Rossiter-McLaughlin and exoplanet transmission spectroscopy

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• Calibration of the [C/N] and [Y/Mg] chemical clocks with asteroseismic ages from the TESS space mission
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