论文标题
Co-H2O碰撞在彗星CO的旋转激发中的影响
The effect of CO-H2O collisions in the rotational excitation of cometary CO
论文作者
论文摘要
我们介绍了H2O在动力学温度范围5-100 K中对CO旋转激发的第一个准确速率系数。统计绝热通道方法（SACM）与高级刚性刚性COH2O CO-H2O分子间电位表面相结合。考虑到Para-H2O和Ortho-H2O的前11个旋转水平和前8个旋转水平之间的过渡。将我们的速率系数与文献的先前数据进行了比较，并且还将其纳入了简单的非LTE彗星昏迷模型中，包括碰撞引起的过渡，太阳辐射泵送和辐射衰减。我们发现，碰撞数据中的不确定性对10^3-10^8 cm^-3范围内的H2O密度的CO种群分布有重大影响。我们还表明，H2O的旋转分布在CO激发中起重要作用（由于CO和H2O的相关能量转移），而H2O的正para比的影响可忽略不计。
We present the first accurate rate coefficients for the rotational excitation of CO by H2O in the kinetic temperature range 5-100 K. The statistical adiabatic channel method (SACM) is combined with a high-level rigid-rotor CO-H2O intermolecular potential surface. Transitions among the first 11 rotational levels of CO and the first 8 rotational levels of both para-H2O and ortho-H2O are considered. Our rate coefficients are compared to previous data from the literature and they are also incorporated in a simple non-LTE model of cometary coma including collision-induced transitions, solar radiative pumping and radiative decay. We find that the uncertainties in the collision data have significant influence on the CO population distribution for H2O densities in the range 10^3-10^8 cm^-3. We also show that the rotational distribution of H2O plays an important role in CO excitation (owing to correlated energy transfer in both CO and H2O), while the impact of the ortho-to-para ratio of H2O is found to be negligible.
