2020A&A...634A..55G


Query : 2020A&A...634A..55G

2020A&A...634A..55G - Astronomy and Astrophysics, volume 634A, 55-55 (2020/2-1)

Observational constraints on the origin of the elements. II. 3D non-LTE formation of Ba II lines in the solar atmosphere.

GALLAGHER A.J., BERGEMANN M., COLLET R., PLEZ B., LEENAARTS J., CARLSSON M., YAKOVLEVA S.A. and BELYAEV A.K.

Abstract (from CDS):

Context. The pursuit of more realistic spectroscopic modelling and consistent abundances has led us to begin a new series of papers designed to improve current solar and stellar abundances of various atomic species. To achieve this, we have begun updating the three-dimensional (3D) non-local thermodynamic equilibrium (non-LTE) radiative transfer code, MULTI3D, and the equivalent one-dimensional (1D) non-LTE radiative transfer code, MULTI 2.3. Aims. We examine our improvements to these codes by redetermining the solar barium abundance. Barium was chosen for this test as it is an important diagnostic element of the s-process in the context of galactic chemical evolution. New BaII + H collisional data for excitation and charge exchange reactions computed from first principles had recently become available and were included in the model atom. The atom also includes the effects of isotopic line shifts and hyperfine splitting. Methods. A grid of 1D LTE barium lines were constructed with MULTI 2.3 and fit to the four BaII lines available to us in the optical region of the solar spectrum. Abundance corrections were then determined in 1D non-LTE, 3D LTE, and 3D non-LTE. A new 3D non-LTE solar barium abundance was computed from these corrections. Results. We present for the first time the full 3D non-LTE barium abundance of A(Ba)=2.27±0.02± 0.01, which was derived from four individual fully consistent barium lines. Errors here represent the systematic and random errors, respectively.

Abstract Copyright: © A. J. Gallagher et al. 2020

Journal keyword(s): hydrodynamics - radiative transfer - line: formation

Simbad objects: 2

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Number of rows : 2
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 GrW 170817 GWE 13 09 48.0850 -23 22 53.343           ~ 1594 0
2 * alf Lyr dS* 18 36 56.33635 +38 47 01.2802 0.03 0.03 0.03 0.07 0.10 A0Va 2623 0

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2023.02.02-18:36:15

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