M型AGB星的星周水蒸气：来自Odin获得的H2O（1_10 - 1_01）线的约束
Circumstellar water vapour in M-type AGB stars: Constraints from H2O(1_10 - 1_01) lines obtained with Odin
摘要：
目的：利用Odin卫星获得了三颗M型AGB星的光谱分辨星周H2O（1_10 - 1_01）谱线。这提供了额外的强约束的属性拱星H2O和拱星信封。方法：采用ISO和Odin卫星H2O谱线数据作为辐射转移模型的约束条件。特别考虑到光谱分辨的奥丁线的轮廓，和第一激发振动态的伸缩模式（nu 1 =1和nu 3 =1）上导出的丰度的激发的效果进行了估计。一个非本地的，辐射转移代码的基础上的ALI形式主义。结果：H2O丰度估计值与以前的估计值一致。Odin数据集的纳入对H2O包络的大小有更强的约束。的H2O（1_10 - 1_01）线配置文件需要显着减少的膨胀速度相比，终端气体膨胀速度确定在模型中的CO无线电线发射，表明H2O发射线探测风仍在加速的区域。包括nu 3 =1状态显着降低了低质量损失率物体的估计丰度。这表明了详细建模的重要性，特别是在3至6微米范围内的红外光谱的细节，以估计准确的拱星H2O丰度。结论：光谱分辨的星周水发射线是研究渐近巨星支星周包层内区物理和化学的重要探针。在即将到来的赫歇尔/HIFI任务的光谱范围内的H2O发射线的预测表明，这些意见将是非常重要的，在这方面。
英文摘要：
Aims: Spectrally resolved circumstellar H2O(1_10 - 1_01) lines have been obtained towards three M-type AGB stars using the Odin satellite. This provides additional strong constrains on the properties of circumstellar H2O and the circumstellar envelope. Methods: ISO and Odin satellite H2O line data are used as constraints for radiative transfer models. Special consideration is taken to the spectrally resolved Odin line profiles, and the effect of excitation to the first excited vibrational states of the stretching modes (nu1=1 and nu3=1) on the derived abundances is estimated. A non-local, radiative transfer code based on the ALI formalism is used. Results: The H2O abundance estimates are in agreement with previous estimates. The inclusion of the Odin data sets stronger constraints on the size of the H2O envelope. The H2O(1_10 - 1_01) line profiles require a significant reduction in expansion velocity compared to the terminal gas expansion velocity determined in models of CO radio line emission, indicating that the H2O emission lines probe a region where the wind is still being accelerated. Including the nu3=1 state significantly lowers the estimated abundances for the low-mass-loss-rate objects. This shows the importance of detailed modelling, in particular the details of the infrared spectrum in the range 3 to 6 micron, to estimate accurate circumstellar H2O abundances. Conclusions: Spectrally resolved circumstellar H2O emission lines are important probes of the physics and chemistry in the inner regions of circumstellar envelopes around asymptotic giant branch stars. Predictions for H2O emission lines in the spectral range of the upcoming Herschel/HIFI mission indicate that these observations will be very important in this context.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
