The impact of protostellar outflows on the interstellar matter

原恒星流出对星际物质的影响

• 批准号: 203331591
• 负责人: Dr. Bringfried Stecklum
• 金额: --
• 依托单位: Thüringer Landessternwarte Tautenburg (TLS) - Karl-Schwarzschild-Observatorium
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203331591?language=en
• 关键词: impact; protostellar; outflows; interstellar; matter

Turbulent support of molecular clouds might be one solution to the problem why the observed star formation rate is much lower than expected if molecular clouds would collapse on their free-fall time scale. The prerequisite, however, is that the turbulent energy which is being dissipated in shocks can be replenished. Protostars eject a certain fraction of the descending matter by bipolar jets and outflows at high speed. Thus, they are considered as potential drivers for stirring the turbulence. However, there are controversial views in the literature whether or not jets and outflows can provide sufficient input to actually stabilize clouds. In order to help clarifying the role of outflows in this context we propose a thorough study of the impact of protostellar outflows on the ISM. In order to assess physical parameters of outflows such as energy and momentum we will combine near-infrared and radio data of welI-investigated regions, use excitation models to account for missing transitions, and keep the time-variability of the flows as well as their geometry in mind. We will apply the derived results for outflows identified in H2 surveys (GLIMPSE follow-up, UWISH2) to improve the overall statistics. Moreover, we propose to specify and procure H2 filters for VISTA to perform a southern wide-field Galactic plane survey which will supplement ongoing/future ISM studies with Herschel, and ground-based facilities, e.g. ALMA.

如果分子云在自由落体时间尺度上塌缩，分子云的湍流支持可能是解决为什么观测到的恒星形成速率远低于预期的问题的一种解决方案。但前提是激波中消耗的湍流能量能够得到补充。原恒星通过双极喷流和高速流出喷射出一定比例的下降物质。因此，它们被认为是搅动动荡的潜在驱动力。然而，文献中对于喷流和流出是否能够提供足够的输入来真正稳定云层存在争议。为了帮助澄清流出在这种情况下的作用，我们建议对原恒星流出对 ISM 的影响进行彻底研究。为了评估流出的物理参数，例如能量和动量，我们将结合深入研究区域的近红外和无线电数据，使用激励模型来解释丢失的跃迁，并保持流动的时间变化及其心中的几何。我们将应用 H2 调查（GLIMPSE 后续行动，UWISH2）中确定的流出的导出结果来改进整体统计数据。此外，我们建议为 VISTA 指定和采购 H2 过滤器，以执行南部广域银河平面勘测，这将补充赫歇尔正在进行/未来的 ISM 研究和地面设施，例如。阿尔玛。