A Study of Circumstellar Disks Using Infrared Molecular Diagnostics

AST0307497PI RICRITER这个项目集中于对主序前恒星和主序恒星的光谱观测，试图确定与我们太阳系中陆地和气体巨行星的轨道相当的半径的圆盘的特征。通过在高光谱分辨率下观察分子氢和其他简单气体分子的多重跃迁，研究小组将对温度、气体和尘埃之间的混合程度以及原行星盘的化学状态等性质施加限制。大多数观测将使用德克萨斯梯形交叉回声光谱仪进行，这是一种高分辨率中红外光谱仪，能够在4至25微米波长区域进行灵敏、非常高的光谱分辨率观测。使用该仪器，还将搜索选定的来源，以寻找水蒸气、一氧化碳、甲烷和氨的转变。比较不同激发能量下的发射线有助于洞察不同半径下的圆盘性质。由于这项研究调查的是行星系统的起源和原行星盘内生物前分子的演化，所以任何关于正在形成的行星的光谱探测以及关于此类行星附近的水和简单有机物种的信息都是公众感兴趣的。调查员将继续担任该仪器与天文学界的联络点，维护和改进他开发的软件，在望远镜上进行观测，并协助减少和分析数据。这项研究将包括研究生和本科生参与该项目。其目标是通过让学生参与一个相对较小的研究小组来鼓励未来仪器工作者的发展，该小组设计、建造、维护和使用最先进的天文仪器。

AST 0307497PI RichterThis project concentrates on spectroscopic observations of pre-main-sequence and main-sequence stars in an attempt to characterize disks at radii comparable to the orbits of terrestrial and gas giant planets in our own solar system. By observing multiple transitions of molecular hydrogen and other simple, gaseous molecules at high spectral resolution, the research team will place constraints on properties such as the temperature, the level of mixing between gas and dust, and the chemical state of protoplanetary disks. Most of the observations will be carried out using the Texas Echelon Cross Echelle Spectrograph, a high-resolution, mid-infrared spectrograph capable of sensitive, very high spectral resolution observations in the 4 to 25 micrometer wavelength regions. Using this instrument, selected sources will also be searched for water vapor, carbon monoxide, methane, and ammonia transitions. Comparing emission lines at very different excitation energies will help provide insight into the disk properties at varying radii.Broader Impacts. Because this research investigates the origins of planetary systems and the evolution of pre-biotic molecules within proto-planetary disks, any spectroscopic detection of forming planets and information regarding water and simple organic species near such planets are of interest to the general public. The investigator will continue to serve as the point of contact for this instrument with the astronomical community, maintain and improve the software he developed, conduct observations at the telescope, and assist in the reduction and analysis of data. This research will include graduate and undergraduate students in the project. The goal is to encourage the development of future instrumentalists by involving students in a relatively small research group that designs, builds, maintains, and uses forefront astronomical instruments.