Physical properties of the fluorine and neutron-capture element-rich PN Jonckheere 900
Physical properties of the fluorine and neutron-capture element-rich PN Jonckheere 900
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DOI：
10.1093/mnras/stz3147
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发表时间：
2019-11
影响因子：
4.8
通讯作者：
M. Otsuka;S. Hyung
中科院分区：
文献类型：
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作者：
M. Otsuka;S. Hyung
我们对年轻的富碳行星状星云Jonckheere 900（J 900）进行了详细的光谱分析，以表征中心星星和星云的性质。导出的17个元素丰度，我们提出了第一次测定的8个元素丰度。我们首次在J 900中检测到[F iv] 4059.9 Å、[F v] 13.4 μm和[Rb iv] 5759.6 Å谱线。J 900表现出F和中子俘获元素Se、Kr、Rb和Xe的大幅增强。我们使用新探测到的中红外H2线研究了H2区的物理条件，同时也使用了以前测量到的近红外H2线，这些线表明温暖（670 K）和炎热（3200 K）的温度区域。我们建立了光谱能量分布（SED）模型，以符合所有观测到的量。我们发现大约67%的尘埃和气体成分（分别为4.5 × 10−4 M和0.83 M）存在于电离前沿之外，这表明光解区域在理解恒星质量损失方面的关键重要性。最佳拟合的SED模型表明，这颗恒星的前身是从一颗初始质量为2.0 M的星星演化而来，该恒星处于燃烧氦的壳层阶段。事实上，推导出的元素丰度模式与渐近巨星分支星星核合成模型对一颗2.0 M质量的星星（Z = 0.003，部分混合区质量为6.0 × 10−3 M质量）的预测一致。我们的研究表明，如何准确地确定C/F/Ne/中子捕获元素和气体/尘埃质量的丰度，帮助我们了解PN祖先的起源和内部演化。
We performed detailed spectroscopic analyses of a young C-rich planetary nebula (PN) Jonckheere 900 (J900) in order to characterize the properties of the central star and nebula. Of the derived 17 elemental abundances, we present the first determination of eight elemental abundances. We present the first detection of the [F iv] 4059.9 Å, [F v] 13.4 μm, and [Rb iv] 5759.6 Å lines in J900. J900 exhibits a large enhancement of F and neutron-capture elements Se, Kr, Rb, and Xe. We investigated the physical conditions of the H2 zone using the newly detected mid-IR H2 lines while also using the previously measured near-IR H2 lines, which indicate warm (∼670 K) and hot (∼3200 K) temperature regions. We built the spectral energy distribution (SED) model to be consistent with all the observed quantities. We found that about 67 per cent of all dust and gas components (4.5 × 10−4 M⊙ and 0.83 M⊙, respectively) exists beyond the ionization front, indicating the critical importance of photodissociation regions in understanding stellar mass loss. The best-fitting SED model indicates that the progenitor evolved from an initially ∼2.0 M⊙ star that had been in the course of the He-burning shell phase. Indeed, the derived elemental abundance pattern is consistent with that predicted by an asymptotic giant branch star nucleosynthesis model for a 2.0 M⊙ star with Z = 0.003 and partial mixing zone mass of 6.0 × 10−3 M⊙. Our study demonstrates how accurately determined abundances of C/F/Ne/neutron-capture elements and gas/dust masses help us understand the origin and internal evolution of the PN progenitors.