Laboratory measurements of the far-infrared to millimeter dust opacity at low temperatures

低温下远红外至毫米级灰尘不透明度的实验室测量

• 批准号: 203319420
• 负责人: Dr. Frank Lewen
• 金额: --
• 依托单位: Astrophysikalisches Institut und Universitätssternwarte
• 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 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203319420?language=en
• 关键词: Laboratory; measurements; far; infrared; millimeter

The thermal emission of cold dust in the far infrared up to the millimeter range is an important source of information for studies of the spatial distribution of the interstellar medium. The interpretation of observations in this spectral range, as they were or are performed with Herschel, Planck, and ALMA, depends on the exact knowledge of the emission properties of the dust particles, i.e. the dust opacity. The available opacity data, however, are based on relatively few laboratory measurements for some selected materials only and on a still quite poor understanding of the underlying physical effects. Although the strong influence of temperature on the sub-millimeter opacity is known in principle, so far only a few measurements at low temperatures have been carried out. The aim of the project is to broaden this data base by laboratory measurements on important interstellar-dust materials such as amorphous silicates of different iron content (phase I), carbonaceous materials (phase II), and for mixtures e.g. of silicate, ice and carbon- or iron-based materials. The influence of temperature, of inhomogeneous compositions and of particle agglomeration on the opacity will be investigated in detail. Understanding the physical interrelations and improving the astrophysical dust models requires measurements in a wide wavelength range, which we achieve by combining experiences and devices from two institutes (Jena and Cologne).

冷尘埃在远红外线至毫米范围内的热辐射是研究星际介质空间分布的重要信息来源。在这个光谱范围内的观测结果的解释，就像赫歇尔、普朗克和阿尔马所做的那样，取决于对尘埃粒子发射特性的确切了解，即尘埃不透明度。然而，现有的不透明度数据仅基于对某些选定材料的相对较少的实验室测量，并且对潜在的物理效应的理解仍然很差。虽然温度对亚毫米不透明度的强烈影响原则上是已知的，但到目前为止，只有少数在低温下进行了测量。该项目的目的是通过对重要的星际尘埃材料进行实验室测量来扩大这一数据库，这些材料包括不同铁含量的无定形硅酸盐（第一阶段）、含碳材料（第二阶段）以及硅酸盐、冰和碳基或铁基材料等混合物。将详细研究温度、不均匀组成和颗粒团聚对不透明度的影响。了解物理的相互关系和改善天体物理尘埃模型需要在很宽的波长范围内的测量，这是我们通过结合两个研究所（耶拿和科隆）的经验和设备来实现的。