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的时间尺度上坍缩，那么为什么观测到的恒星形成率比预期的要低得多，分子云的湍流支持可能是一个解决方案。然而，前提是在冲击中耗散的湍流能量能够得到补充。原恒星以双极喷射和高速流出的方式喷射出一定比例的下降物质。因此，它们被认为是搅动湍流的潜在驱动因素。然而，射流和喷流是否能够提供足够的输入来实际稳定云，在文献中存在争议。为了帮助澄清外流在这种情况下的作用，我们建议对原恒星外流对ISM的影响进行深入研究。为了评估流出物的物理参数，如能量和动量，我们将结合井调查区域的近红外和无线电数据，使用激励模型来解释缺失的过渡，并保持流动的时间可变性以及它们的几何形状。我们将把导出的结果应用于H2调查（GLIMPSE随访，UWISH2）中确定的流出，以改善整体统计数据。此外，我们建议为VISTA指定和采购H2过滤器，以执行南部宽视场银河平面调查，这将补充正在进行/未来的ISM研究与赫歇尔和地面设施，如ALMA。