Design and Application of HighResolution and MultiobjectSpectrographs:Dynamical Studies of Open Clusters
Design and Application of HighResolution and MultiobjectSpectrographs:Dynamical Studies of Open Clusters
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高分辨率多目标光谱仪的设计与应用:疏散星团的动力学研究
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发表时间：
2008
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通讯作者：
Fűrész Gábor
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作者：
Fűrész Gábor
我写这篇论文的目的不仅仅是总结和记录我毕业以来所学到的东西和成就。我的目的是为读者提供一个全面的
介绍了现代天文摄谱仪设计的理论和实践，并给出了一些应用实例。这里的“全面”一词并不意味着我试图涵盖设计过程的每一个细节，但我希望提供所有必要的理论背景，以遵循并证明我与CfA OIR仪器组合作建造的特定光谱仪的设计和建造步骤。因此，这篇论文（第一部分）的一个重要部分都是关于仪器的。第一章可能看起来太过回到基础，但是，我想再次帮助读者了解几乎所有的理论背景信息。与此同时
本章介绍的是一种特殊类型的摄谱仪：高分辨率、高通量、单目标光纤光栅--这是第二章的主题。通过TRES（Tillinghast反射器中阶梯摄谱仪）的例子，我展示了如何将理论应用于设计和施工。TRES不久前刚刚投入使用，所以我几乎没有机会描述仪器的特征，进行一些科学观察。然而，我能够以一些初步结果的讨论来结束这一章。然而，由于TRES的制作花了四年多的时间，
讨论的是另一种工具：Hectochelle。这个多目标的对准和表征，光纤光栅是我作为研究生的第一个任务之一，因此我觉得在这方面的工作（3）。特别是因为用多目标仪器进行的高精度径向速度测量并不简单。这在很大程度上取决于仪器的稳定性和校准系统的设计。讨论这些特定于仪器的细节会得出一些一般性结论，这些结论在文献中没有很好的记录。因此，我试图总结
第4章，这是仪器部分的结论。
第二部分是从仪器制造到科学应用的简短过渡，描述了第三部分中使用的具体数据简化（第5章）和分析（6）工具。主要重点是描述如何合成光谱的网格被用来确定最准确的径向速度，并获得天体物理参数的恒星目标。第三部分介绍了Hectochelle的科学应用：利用它的多目标能力，收集疏散星团中数百个恒星的光谱，揭示其运动学结构。因为大多数恒星都是在星团中形成的，所以在任何关于星星形成机制的研究中，星团形成的过程都是重要的。观测非常年轻的星系团可以提供线索的初始条件的集群形成，如果集群没有动态放松。为了实现这个目标，我研究了其中两个非常年轻的系统，NGC 2264（第8章）和猎户座星云团（第9章）。这些项目的成果是运动学亚结构的第一个直接证据，可能是原始等级制度遗留下来的。第三项研究是关于一个更进化和更松弛的星团，M38（NGC 1912）。尽管它的年龄很大，但在这个系统中有一些动力学上的“热量”，可能是由附近的另一个星团NGC 1907引起的。在第10章中，我展示了一些有趣的发现，关于这个集群对的运动学。
最后，在第11章中，我列出了我参与的一些正在进行的仪器和科学项目，这些项目是本文详细讨论的主题的延续。
My intention writing this thesis was not just to summarize and document what I have learned and accomplished since graduation. I was rather aiming to provide the reader with a comprehensive
description on the theory and practice of modern astronomical spectrographs design, and to present some application examples of such instrument. The word “comprehensive” in this context does not mean I tried to cover every single detail of the design process, but I was hoping to give all the theoretical background necessary to follow and justify the steps of the design and construction of a specific spectrograph I built in collaboration with the CfA OIR instrumental group. A significant fraction of this thesis (Part I) is therefore all about instrumentation. Chapter 1 might seem going too far back to the basics, but, again, I wanted to aid the reader with almost all theoretical background information. At the same time
this introductory chapter is a little bit biased towards a specific type of spectrographs: a high resolution, high throughput, single object fiber-fed echelle – the subject of chapter 2. Through the example of TRES (the Tillinghast Reflector Echelle Spectrograph) I show how the theory applies to design and construction. TRES was just commissioned not so long ago, and so I barely had the chance to characterize the instrument, to carry out some scientific observations. Nevertheless I am able to close that chapter with the discussion of some initial results. However, since the making of TRES took more than four years, the tool for the science examples
discussed is an other instrument: Hectochelle. The alignment and characterization of this multi-object, fiber fed echelle was one of my first tasks as a graduate student, therefore I felt to spare a chapter (3) on this work. Especially since high precision radial velocity measurements carried out with multi-object instruments is not straightforward. A lot depends on instrumental stability and calibration system design. Discussing these instrument-specific details leads to some general conclusions, which are not well documented in the literature. Therefore I attempt to summarize
these in chapter 4, and this concludes the Instrumentation part.
Part II is a short transition from instrument building to science applications, describing the specific data reduction (chapter 5) and analysis (6) tools used in Part III. The main emphasis is on describing how a grid of synthetic spectra is used to determine the most accurate radial velocities and derive astrophysical parameters for the stellar targets. In Part III science applications of Hectochelle are presented: utilizing the multi-object ca-pability for collecting hundreds of stellar spectra in open clusters in order to unveil kinematical structure. Because most stars are formed in clusters the processes responsible for cluster formation are important to include in any consideration of the mechanisms of star formation. Observations of very young clusters can provide clues to the initial conditions of cluster formation if the cluster has not dynamically relaxed. With this goal I have studied two of these very young systems, NGC 2264 (chapter 8) and the Orion Nebula Cluster (chapter 9). The outcome of these projects were the first direct evidence of kinematical substructure, likely left over from the primordial hierarchy. A third study is about a more evolved and relaxed cluster, M38 (NGC 1912). Despite of its age there is some dynamical “heat” in that system, likely caused by an other nearby cluster, NGC 1907. In chapter 10 I show some interesting findings regarding the kinematics of this cluster pair.
To conclude, in chapter 11, I list some ongoing instrumental and science projects I am involved in, which are clear continuation of those topics discussed in detail throughout this thesis.