RUI: Experiments on Cooled Cosmic Dust Analogs to Determine their Optical Properties in the Millimeter/Sub-Millimeter

该项目将研究低温下宇宙模拟尘埃的毫米/亚毫米光学性质。将购买一台干式制冷机，这样该项目的工作就可以继续进行，而不需要支付易腐烂的冷冻剂的费用。此外，PI的研究实验室还将建造一台专门为这项工作设计的傅里叶变换光谱仪。一旦这些仪器就位，将使用一项创新的研究计划来测量许多尘埃样本的毫米/亚毫米不透明度和发射率，无论是内部制造的还是从外部小组获得的。这项工作的主要目标是：(A)利用观测宇宙学领域开发的丰富工具和专业知识，以前所未有的精度测量上述性质；(B)分析不同方法和不同研究人员在相同实验条件下产生的尘埃种类，以清楚地了解样本之间的共同趋势和基本差异；以及(C)实施有效的实验方案，分析大量候选尘埃，这自然会导致建立关于测量性质的数据库。在可见光波长，尘埃遮盖了许多有趣的天文环境，如分子云、恒星形成区、被尘埃包裹的年轻恒星和老恒星，以及早期宇宙中年轻的超发光星系。毫米/亚毫米光谱区域是研究这些天体的一个很好的区域，因为尘埃在这些波长下更透明。关于星际尘埃性质的信息本身是有用的，因为尘埃是银河系和恒星演化的重要组成部分，也是空间中存在的复杂化学物质的重要组成部分，这些化学物质最终产生了益生菌分子，这些信息可以揭示更多关于被尘埃遮挡的物体/环境的性质。最近的实验室研究表明，毫米/亚毫米光谱范围内尘埃的性质比以前认为的要复杂得多。因此，在能够有把握地解释关于这种环境的天文数据之前，需要对可用作宇宙尘埃的类似物的尘埃种类进行详细的研究，例如本项目将进行的研究。最近，由于阿塔卡马大毫米/亚毫米阵列等新观测站提供了高质量的毫米/亚毫米数据，这一需求得到了加强。

This project will study the millimeter/sub-millimeter optical properties of cosmic analog dusts at low temperatures. A dry cryocooler will be purchased so that work on this project can continue, free from the expenses of perishable cryogens. In addition, a Fourier Transform Spectrometer, designed specifically for this work, will be constructed in PI's research lab. Once these apparati are in place, the mm/sub-mm opacity and emissivity of many dust samples, made internally or obtained from external groups will be measured, using an innovative program of study. The main goals of this work are to (A) utilize the rich set of tools and expertise developed within the observational cosmology community to measure the above properties to unprecedented accuracy, (B) analyze dust species produced by different methods and different investigators under the same experimental conditions in order to clearly understand common trends and basic difference between the samples, and (C) implement an efficient experimental scheme for analyzing a large number of dust candidates, which would naturally lead to the creation of a database on the measured properties.At visible wavelengths, dust obscures many interesting astronomical environments such as molecular clouds, star forming regions, young and old stars enveloped by dust, and young ultra-luminous galaxies in the early universe. The mm/sub-mm spectral region is a good regime to study these objects because dust is more transparent at these wavelengths. Information on the nature of interstellar dust is useful in and of itself because dust is an important component in galactic and stellar evolution as well as in the complex chemistry present in space that ultimately gives rise to prebiotic molecules, and this information can reveal more about the nature the objects/environments that are obscured by dust. Recent laboratory studies have shown that the properties of dust in the mm/sub-mm spectral region is more complicated than previously thought. Therefore, detailed studies dust species that can serve as analogs for cosmic dust such as those that will be undertaken in this project are needed before astronomical data on such environments can be interpreted with any confidence. This need has been intensified recently due to the availability high-quality mm/sub-mm data from new observatories such as the Atacama Large Millimeter/Submillimeter Array.