Star Formation out of the Magnetised Interstellar Medium

磁化星际介质中的恒星形成

• 批准号: 319967414
• 负责人: Professor Dr. Robi Stefan Banerjee
• 金额: --
• 依托单位: Hamburger Sternwarte
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/319967414?language=en
• 关键词: Star; Formation; out; Magnetised; Interstellar

Magnetic fields are an elemental part of the interstellar medium (ISM) which have a large impact on the dynamics of the ISM on various spatial scales. One long-standing issue is their influence on the formation of stars in galaxies. Similarly to thermal pressure, magnetic fields prevent contraction of otherwise self-gravitating gas clumps if they are strong enough. Therefore, gaseous overdensities must be magnetically supercritical, quantified by the mass-to-flux ratio, to collapse and to subsequently allow the formation of stars. There is increasing evidence that the ISM-field is rather strong (B > 6 muG) which gives rise to the question how supercritical cloud cores can be generated? To answer this question is the goal of this project. Within this proposed project we will test the two possible answers to this issue, namely the ambipolar diffusion (AD) mediated process, where locally the mass-to-flux is increased and the accumulation process, where gas is gathered over large distances. Therefore, we will study in detail the physics which impacts the AD-model (e.g. chemical and radiative ionisation processes) and we will self-consistently probe the accumulation process with global galactic simulations.

磁场是星际介质（ISM）的基本组成部分，它在不同的空间尺度上对ISM的动力学有很大的影响。一个长期存在的问题是它们对星系中恒星形成的影响。与热压力类似，磁场如果足够强，就会阻止自引力气体团的收缩。因此，气体超密度必须是磁超临界的，由质量与通量比来量化，才能坍缩并随后形成恒星。越来越多的证据表明ISM场相当强（B > 6 μ G），这就产生了如何产生超临界云核的问题。回答这个问题是本项目的目标。在这个拟议的项目中，我们将测试这个问题的两个可能的答案，即双极扩散（AD）介导的过程，其中局部的质量流量增加和积累过程，其中气体在很大的距离上聚集。因此，我们将详细研究影响AD模型的物理学（例如化学和辐射电离过程），我们将自洽地探测全球星系模拟的积累过程。