Simulation of the formation and morphology of ice mantles on interstellar grains
Simulation of the formation and morphology of ice mantles on interstellar grains
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DOI：
10.1086/521014
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发表时间：
2007-10-10
影响因子：
4.9
通讯作者：
Herbst, Eric
中科院分区：
文献类型：
--
作者：
Cuppen, H. M.;Herbst, Eric
尽管人们对星际尘埃颗粒表面发生的化学反应仍然知之甚少，但它深刻地影响着星际介质中分子的生长。一组重要的表面反应在寒冷而致密的地区产生了许多单层的冰幔。单分子层主要是水冰，但也含有CO，CO2，偶尔甲醇，以及次要成分。本文计算了不同星际云物理条件下水冰主导地幔的产生速率，并首次给出了星际冰形态的图像。为此，连续时间随机游走蒙特卡罗模拟技术已被使用。视消光、密度、气体和颗粒温度是变化的。结果表明，我们的随机方法可以重现的重要观察，冰地幔只生长在密集的地区。
Although still poorly understood, the chemistry that occurs on the surfaces of interstellar dust particles profoundly affects the growth of molecules in the interstellar medium. An important set of surface reactions produces icy mantles of many monolayers in cold and dense regions. The monolayers are dominated by water ice, but also contain CO, CO2, and occasionally methanol, as well as minor constituents. In this paper, the rate of production of water-ice-dominated mantles is calculated for different physical conditions of interstellar clouds and for the first time images of the morphology of interstellar ices are presented. For this purpose, the continuous-time random-walk Monte Carlo simulation technique has been used. The visual extinction, density, and gas and grain temperatures are varied. It is shown that our stochastic approach can reproduce the important observation that ice mantles only grow in the denser regions.