The impact of protostellar outflows on the interstellar matter

分子云的湍流支持可能是解决为什么如果分子云在自由落体时间尺度上坍塌，观测到的恒星形成率比预期低得多的问题的一种解决方案。然而，前提条件是激波中正在消散的湍流能量能够得到补充。原恒星通过两极喷流喷出一定比例的下降物质，并以高速流出。因此，它们被认为是搅动湍流的潜在驱动因素。然而，文献中对急流和流出是否能够提供足够的输入来实际稳定云的观点存在争议。为了帮助澄清流出在这方面的作用，我们建议彻底研究原恒星流出对ISM的影响。为了评估外流的物理参数，如能量和动量，我们将结合井下调查区域的近红外和无线电数据，使用激发模型来解释遗漏的跃迁，并考虑到流动的时间变异性及其几何形状。我们将应用H2调查中确定的资金外流的导出结果(Glimse Follow-Follow，UWISH2)来改进整体统计数据。此外，我们建议为Vista指定和采购H2滤光器，以执行南部广域银河平面测量，这将补充正在进行的/未来的ISM研究，以及地面设施，如ALMA。

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.