Electron-impact rotational excitation of H3+: relevance for thermalization and dissociation dynamics.
Electron-impact rotational excitation of H3+: relevance for thermalization and dissociation dynamics.
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H3 的电子撞击旋转激发：与热化和解离动力学的相关性。
DOI：
10.1098/rsta.2006.1863
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Faure A
中科院分区：
文献类型：
--
作者：
Faure A
在低密度天体物理等离子体中，电子可以有效地旋转激发分子离子。分子离子的旋转激发也被证明会影响解离复合（DR）速率系数的测量值。因此，电子碰撞与预计将发挥重要作用，在热化和解离动力学的这种离子，无论是在实验室和空间。用分子R矩阵方法结合绝热核转动近似，计算了10 ~ 10000 K温度范围内电子转动激发的新速率系数。在1000 K以下，去激发率只有几个10− 7 cm 3 s− 1，即与DR的大小相当。电子和中性碰撞之间的竞争进行了讨论的背景下，最近的观测朝向银河系中心源。
Electrons are known to be efficient in rotationally exciting molecular ions in low-density astrophysical plasmas. Rotational excitation of molecular ions has also been shown to affect the measured values of dissociative recombination (DR) rate coefficients. Thus, electron collisions with are expected to play a significant role in thermalization and dissociation dynamics of this ion, both in the laboratory and in space. Using the molecular R-matrix method combined with the adiabatic-nuclei-rotation approximation, we have computed new rate coefficients for the rotational excitation of by electrons at temperatures from 10 to 10 000 K. De-excitation rates are found to amount to a few 10− 7 cm3 s− 1 below 1000 K, ie comparable in magnitude to that of DR. In astrophysical environments where the electron fraction exceeds 10− 4, electron collisions are thus expected to contribute to the non-thermal rotational distribution of. The competition between electron and neutral collisions is discussed in the context of recent observations of towards Galactic centre sources.