论文标题
陆地形成区域中的水紫外线挡层：对二氧化碳排放的影响
Water UV-shielding in the terrestrial planet-forming zone: Implications for carbon dioxide emission
论文作者
论文摘要
二氧化碳是陆地行星形成区域化学和物理学的重要示踪剂。使用已经针对中红外水发射进行了测试的热化学模型，我们重新解释了使用Spitzer观察到的CO2发射。我们发现，水紫外线挡和额外的化学加热都大大减少了发射层中的总二氧化碳柱。水紫外线屏蔽是更有效的效果，将二氧化碳列降低了$ \ sim $ 2的数量级。这些较低的二氧化碳丰度导致二氧化碳到-H2O通量比更接近观察到的值，但是二氧化碳的发射仍然太亮，尤其是相对术语。与H2O发射相比，在水中平面图标外的元素氧的耗竭更强烈影响二氧化碳的发射，从而使二氧化碳至H2O发射与观察到的值一致。我们得出的结论是，用spitzer-ir观察到的二氧化碳发射来自磁盘光球中的薄层，类似于强水线。在此层以下，我们希望不存在CO2，除非通过物理过程补充。这将在$^{13} $ CO2频谱以及JWST-MIRI可以观察到的某些$^{12} $ CO2功能中可见。
Carbon Dioxide is an important tracer of the chemistry and physics in the terrestrial planet forming zone. Using a thermo-chemical model that has been tested against the mid-infrared water emission we re-interpret the CO2 emission as observed with Spitzer. We find that both water UV-shielding and extra chemical heating significantly reduce the total CO2 column in the emitting layer. Water UV-shielding is the more efficient effect, reducing the CO2 column by $\sim$ 2 orders of magnitude. These lower CO2 abundances lead to CO2-to-H2O flux ratios that are closer to the observed values, but CO2 emission is still too bright, especially in relative terms. Invoking the depletion of elemental oxygen outside of the water mid-plane iceline more strongly impacts the CO2 emission than it does the H2O emission, bringing the CO2-to-H2O emission in line with the observed values. We conclude that the CO2 emission observed with Spitzer-IRS is coming from a thin layer in the photo-sphere of the disk, similar to the strong water lines. Below this layer, we expect CO2 not to be present except when replenished by a physical process. This would be visible in the $^{13}$CO2 spectrum as well as certain $^{12}$CO2 features that can be observed by JWST-MIRI.
