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arXiv 1012.1142astro-ph.GA
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ROBO:研究星际介质的模型和代码

ROBO: a Model and a Code for the Study of the Interstellar Medium

T. Grassi, P. Krstic, E. Merlin, U. Buonomo, L. Piovan, C. Chiosi

摘要:

介绍了一个用于研究星际介质的模型ROBO及其配套程序。其目的是提供一个准确的描述的物理演化的ISM和设置一个辅助工具,将插入在NB-TSPH(NB-TSPH)模拟的大尺度结构在宇宙学的背景下或个别星系的形成和演化。ISM模型由气体和尘埃组成。气体的化学成分由包括大量物质(氢和氘基分子、氦和金属)的反应网络调节。给出了$\mathrm H^+$和$\mathrm H_2$碰撞中电荷转移的新反应速率。灰尘包含标准的混合物的碳颗粒(石墨颗粒和多环芳烃)和硅酸盐的模型如下的形成和破坏的几个过程。该模型考虑到一个准确的治疗的冷却过程中,几个物理机制的基础上,最近在文献中报道的冷却功能。该模型适用于广泛的输入参数和重要的量描述的气体和粉尘的物理状态的结果。将结果组织在适合于人工神经网络(ANN)的数据库中。一旦经过训练,人工神经网络产生的结果与机器人获得的结果相同,而且精度很高。我们计划开发适合应用NB-TSPH模拟宇宙学结构和/或星系的人工神经网络。

英文摘要:

We present ROBO, a model and its companion code for the study of the interstellar medium (ISM). The aim is to provide an accurate description of the physical evolution of the ISM and to set the ground for an ancillary tool to be inserted in NBody-Tree-SPH (NB-TSPH) simulations of large scale structures in cosmological context or of the formation and evolution of individual galaxies. The ISM model consists of gas and dust. The gas chemical composition is regulated by a network of reactions that includes a large number of species (hydrogen and deuterium based molecules, helium, and metals). New reaction rates for the charge transfer in $\mathrm H^+$ and $\mathrm H_2$ collisions are presented. The dust contains the standard mixture of carbonaceous grains (graphite grains and PAHs) and silicates of which the model follows the formation and destruction by several processes. The model takes into account an accurate treatment of the cooling process, based on several physical mechanisms, and cooling functions recently reported in the literature. The model is applied to a wide range of the input parameters and the results for important quantities describing the physical state of the gas and dust are presented. The results are organized in a database suited to the artificial neural networks (ANNs). Once trained, the ANNs yield the same results obtained by ROBO, with great accuracy. We plan to develop ANNs suitably tailored for applications to NB-TSPH simulations of cosmological structures and/or galaxies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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