A Study of Circumstellar Disks Using Infrared Molecular Diagnostics

这个项目集中于对主序前恒星和主序恒星的光谱观测，试图在与我们太阳系中类地行星和气态巨行星的轨道半径相当的半径上描绘圆盘的特征。通过在高光谱分辨率下观察氢分子和其他简单气体分子的多次跃迁，研究小组将对温度、气体和尘埃之间的混合水平以及原行星盘的化学状态等特性施加限制。大部分观测将使用德克萨斯梯队交叉梯队光谱仪进行，这是一种高分辨率中红外光谱仪，能够在4到25微米波长区域进行敏感的、非常高的光谱分辨率观测。使用这台仪器，选定的源也将搜索水蒸气，一氧化碳，甲烷和氨的转变。比较不同激发能下的发射谱线将有助于深入了解不同半径下的圆盘性质。更广泛的影响。由于这项研究调查了行星系统的起源和原行星盘中生命前分子的演化，因此任何对形成行星的光谱探测以及有关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。研究者将继续作为这台仪器与天文团体的联络点，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。目标是通过让学生参与设计、建造、维护和使用前沿天文仪器的一个相对较小的研究小组，鼓励未来仪器学家的发展。

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.