From Solar System Formation Theory "Kyoto Model" to General Theory of Planetary Systems "Kobe Model"

详细的模型的密度和温度分布的气体和尘埃在原行星盘构造考虑到X射线和紫外线照射从中央金牛座T星星，以及尘埃大小的增长和沉降向磁盘中平面。尘埃颗粒的空间和尺寸分布的数值计算通过求解沉降尘埃颗粒的凝聚方程，其结果是，在磁盘中的每单位体积的气体的尘埃颗粒的质量和总表面积是非常小的，除了在中平面。利用导出的盘的物理结构计算了H_2能级布居和谱线发射。X射线辐射是内部盘和表面层中的气体的主要加热源，而UV加热占主导地位。如果中心星星有强的X射线和弱的紫外辐射，H_2能级布居受X射线泵浦控制，X射线诱导的跃迁线是可以观测到的。如果紫外线照射很强，则能级粒子数由热碰撞或紫外线泵浦控制，这取决于尘埃的性质。当尘埃粒子在圆盘中演化时，圆盘表面处的气体温度下降，因为颗粒光电加热变得不那么有效。这使得水平总体从LTE分布改变为非LTE分布，这导致线比率的改变。我们的研究结果表明，尘埃在原行星盘的演化可以通过H_2线比观察。在强紫外和X射线照射下，尘埃盘的发射谱线很强，并且尘埃盘中含有小的尘埃颗粒，这类尘埃盘将是观测H_2发射的良好靶。

Detailed models for the density and temperature profiles of gas and dust in protoplanetary disks are constructed by taking into account X-ray and UV irradiation from a central T Tauri star, as well as dust size growth and settling toward the disk midplane. The spatial and size distributions of dust grains are numerically computed by solving the coagulation equation for settling dust particles, with the result that the mass and total surface area of dust grains per unit volume of the gas in the disks are very small, except at the midplane. The H_2 level populations and line emission are calculated using the derived physical structure of the disks. X-ray irradiation is the dominant heating source of the gas in the inner disk and in the surface layer, while the UV heating dominates otherwise. If the central star has strong X-ray and weak UV radiation, the H_2 level populations are controlled by X-ray pumping, and the X-ray-induced transition lines could be observable. If the UV irradiation is strong, the level populations are controlled by thermal collisions or UV pumping, depending on the dust properties. As the dust particles evolve in the disks, the gas temperature at the disk surface drops because the grain photoelectric heating becomes less efficient. This makes the level populations change from LTE to non-LTE distributions, which results in changes to the line ratios. Our results suggest that dust evolution in protoplanetary disks could be observable through the H_2 line ratios. The emission lines are strong from disks irradiated by strong UV and X-rays and possessing small dust grains ; such disks will be good targets in which to observe H_2 emission.