论文标题
陆地形成区域中的水紫外线挡架：水发射的含义
Water UV-shielding in the terrestrial planet-forming zone: Implications from water emission
论文作者
论文摘要
中红外光谱是观察原始星际磁盘的内部行星形成区（内部少数AU）组成的几种方法之一。从理论上讲，当前在磁盘大气中检测到的物种，例如CO，CO2，H2O和C2H2，足以限制磁盘表面中的C/O比。然而，热化学模型在同时繁殖全面检测到的物种方面遇到困难。为了靠近观察到的光谱，我们包括水紫外线挡片以及更有效的化学加热到热化学代码灰尘和线条中。我们发现两者都必须匹配观察到的发射光谱。除了从紫外光子的传统加热外，还需要有效的化学加热，以升高排水层的温度以匹配观察到的水的激发温度。我们发现水紫外线挡块可以停止紫外线光子进入磁盘深处，并用较高的柱冷却下层。这两个效果创建了一个热发出的水层，列为1-10 $ \ times 10^{18} $ cm $^{ - 2} $。这仅是灰尘$τ= 1 $表面的水柱的1-10％，在模型中的中红外波长处，占总水柱的<1％。
Mid-infrared spectroscopy is one of the few ways to observe the composition of the terrestial planet forming zone, the inner few au, of proto-planetary disks. The species currently detected in the disk atmosphere, for example CO, CO2, H2O and C2H2, are theoretically enough to constrain the C/O ratio in the disk surface. However, thermo-chemical models have difficulties in reproducing the full array of detected species in the mid-infrared simultaneously. In an effort to get closer to the observed spectra, we have included water UV-shielding as well as more efficient chemical heating into thermo-chemical code Dust And Lines. We find that both are required to match the observed emission spectrum. Efficient chemical heating, in addition to traditional heating from UV photons, is necessary to elevate the temperature of the water emitting layer to match the observed excitation temperature of water. We find that water UV-shielding stops UV photons from reaching deep into the disk, cooling down the lower layers with higher column. These two effects create a hot emitting layer of water with a column of 1-10$\times 10^{18}$ cm$^{-2}$. This is only 1-10% of the water column above the dust $τ=1$ surface at mid-infrared wavelengths in the models and represents <1% of the total water column.
