1. |
|
|
2. |
- Glasbey, JC, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
3. |
- Tabiri, S, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
4. |
- Bravo, L, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
5. |
|
|
6. |
|
|
7. |
- Albert, Damien, et al.
(author)
-
A Decade with VAMDC : Results and Ambitions
- 2020
-
In: Atoms. - : MDPI. - 2218-2004. ; 8:4
-
Journal article (peer-reviewed)abstract
- This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&M data from more than one database. Finally, we present our vision for the future of VAMDC.
|
|
8. |
- Magg, Ekaterina, et al.
(author)
-
Observational constraints on the origin of the elements IV. Standard composition of the Sun
- 2022
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 661
-
Journal article (peer-reviewed)abstract
- Context. The chemical composition of the Sun is required in the context of various studies in astrophysics, among them in the calculation of standard solar models (SSMs) used to describe the evolution of the Sun from the pre-main-sequence to its present age. Aims. In this work, we provide a critical re-analysis of the solar chemical abundances and corresponding SSMs. Methods. For the photospheric values, we employed new high-quality solar observational data collected with the IAG facility, state-of-the art non-equilibrium modelling, new oscillator strengths, and different atmospheric models, including the MARCS model, along with averages based on Stagger and CO5BOLD 3D radiation-hydrodynamics simulations of stellar convection. We performed new calculations of oscillator strengths for transitions in O I and N I. For O I, which is a critical element with regard to the interior models, calculations were carried out using several independent methods. We investigated our results in comparison with the previous estimates. Results. We find an unprecedented agreement between the new estimates of transition probabilities, thus supporting our revised solar oxygen abundance value. We also provide new estimates of the noble gas Ne abundance. In addition, we discuss the consistency of our photospheric measurements with meteoritic values, taking into account the systematic and correlated errors. Finally, we provide revised chemical abundances, leading to a new value proposed for the solar photospheric present-day metallicity of Z/X=0.0225, which we then employed in SSM calculations. We find that the puzzling mismatch between the helioseismic constraints on the solar interior structure and the model can be resolved thanks to this new chemical composition.
|
|
9. |
- Storm, N., et al.
(author)
-
3D NLTE modelling of Y and Eu : Centre-to-limb variation and solar abundances
- 2024
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 683
-
Journal article (peer-reviewed)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)(3D NLTE) = 2.30 ± 0.03stat ± 0.07syst dex based on observations at all angles and A(Eu) = 0.57 ± 0.01stat ± 0.06syst 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.
|
|