论文标题
太阳和恒星中的铍丰度：非本地热力学平衡效应的作用
Abundance of beryllium in the Sun and stars: The role of non-local thermodynamic equilibrium effects
论文作者
论文摘要
较早的研究表明，局部热力学平衡（LTE）的偏差在太阳和恒星大气中的BE II 313 nm共振线的形成中起较小的作用。原子数据的最新改进允许构建更完整的模型原子，并使用更多最新的原子理物理学重新评估这些主张的有效性。因此，这项研究的主要目标是重新关注非本地热力学平衡（NLTE）在BE II 313.04和313.11 nm共振线形成中的作用。为此，我们构建了一个使用新的原子数据的模型原子。该模型原子包含BE I和II的98个水平和383个辐射过渡，并使用电子和氢的最新碰撞速率。这使其成为用于确定1D NLTE太阳能的最完整模型，并研究NLTE效应在BE II 313 nm共振线形成中的作用。我们发现，与LTE的偏差对太阳和恒星大气中的BE II 313 nm线的强度有重大影响。对于太阳，我们获得了A（Be）_nlte = 1.32 +/- 0.05的1D NLTE，这与A（BE）= 1.31 +/- 0.04的陨石值非常吻合。重要的是，我们发现NLTE效应在FGK恒星中变得重要。此外，具有有效温度和金属性的1D NLTE-LTE丰度校正有明显的变化。因此，与我们先前的理解相反，获得的结果表明，NLTE效应在恒星大气中的线形成中起着重要作用，并且必须在丰富的研究中正确考虑，尤其是在金属贫困的恒星中。
Earlier studies have suggested that deviations from the local thermodynamic equilibrium (LTE) play a minor role in the formation of Be II 313 nm resonance lines in solar and stellar atmospheres. Recent improvements in the atomic data allow a more complete model atom of Be to be constructed and the validity of these claims to be reassessed using more up-to-date atomic physics. The main goal of this study therefore is to refocus on the role of non-local thermodynamic equilibrium (NLTE) effects in the formation of Be II 313.04 and 313.11 nm resonance lines in solar and stellar atmospheres. For this, we constructed a model atom of Be using new atomic data that recently became available. The model atom contains 98 levels and 383 radiative transitions of Be I and Be II and uses the most up-to-date collision rates with electrons and hydrogen. This makes it the most complete model atom used to determine 1D NLTE solar Be abundance and to study the role of NLTE effects in the formation of Be II 313 nm resonance lines. We find that deviations from LTE have a significant influence on the strength of the Be II 313 nm line in solar and stellar atmospheres. For the Sun, we obtained the 1D NLTE Be abundance of A(Be)_NLTE = 1.32+/-0.05, which is in excellent agreement with the meteoritic value of A(Be)=1.31+/-0.04. Importantly, we find that NLTE effects become significant in FGK stars. Moreover, there is a pronounced variation in 1D NLTE-LTE abundance corrections with the effective temperature and metallicity. Therefore, contrary to our previous understanding, the obtained results indicate that NLTE effects play an important role in Be line formation in stellar atmospheres and have to be properly taken into account in Be abundance studies, especially in metal-poor stars.
