Gas in the Planet-Forming Region of Circumstellar Disks: High Dispersion Infrared Spectroscopy and Spectro-Astrometry

Geoffrey Blake博士（加州理工学院）将与莱顿大学的研究人员领导一项合作研究计划，该计划将利用凯克近红外光谱仪（Keck-NIRSPEC）和超大望远镜低温高分辨率红外Echelle光谱仪（VLT-CRIRES）研究原行星盘中气体的性质和演化。年轻恒星周围的星周盘是星星形成和（外）行星科学之间的关键联系。这些盘的物理和化学结构，沿着它们的传输特性和演化时间尺度，在决定什么样的行星系统（如果有的话）可以形成方面起着核心作用。在几十个天文单位（Au）（行星形成区）内部的气体探测器特别需要区分竞争的行星形成模型。虽然对这些区域的气体直接成像需要几年的时间，但红外光谱和光谱天体测量提供了一种替代途径。布莱克博士和其他研究人员最近发现，在4.7微米附近，一氧化碳的基本振转辐射提供了一个在0.5-50 Au区域的环周盘气体的广泛观测诊断。作为这项提议的一部分，将开发的辐射传输工具将使整个天文学界受益。这一研究项目的结果将指导下一代微波/太赫兹和红外望远镜的观测，并应能够构建星周盘行星形成区域的详细和定量模型。该计划还将把地基红外光谱和光谱天体测量推向极限，并将需要优化数据采集，校准和还原例程，以实现接近光子统计所施加的动态范围。这些例行程序将用于广泛的观测方案，包括红外径向速度工作和通过凌日测量确定太阳系外行星大气的特征。 至少有四名研究生和几名本科生将在一个非常跨学科的方式作为本研究计划的一部分进行培训。布莱克博士的团队还积极参与加州理工学院早期教育发展科学和加州理工学院学前科学计划K-12教育项目，并正在为各种年级开发新的教学模块。

Dr. Geoffrey Blake (Calfornia Institute of Technology) will lead a collaborative research program with researchers at Leiden University that will utilize the Keck Near Infrared Spectrometer (Keck-NIRSPEC) and the Very Large Telescope Cryogenic High-Resolution Infrared Echelle Spectrograph (VLT-CRIRES) to study the properties and evolution of the gas in protoplanetary disks. Circumstellar disks around young stars provide the pivotal link between star formation and (exo)-planetary science. The physical and chemical structures of these disks, along with their transport properties and evolutionary timescales, play a central role in determining what sort of planetary system, if any, can be formed. Probes of the gas in the inner few tens of Astronomical Units (AU) (the planet-building zone) are particularly needed to distinguish between competing planetary formation models. While the direct imaging of the gas in such regions lies several years into the future, infrared spectroscopy and spectro-astrometry provide an alternative route. Dr. Blake, and others, have recently shown that the fundamental rovibrational emission from carbon monoxide near 4.7 µm provides a widely observable diagnostic of the gas in the 0.5-50 AU region of circumstellar disks.The radiative transfer tools to be developed as part of this proposal will benefit the entire astronomical community. The results of this research project will guide observations with the next generation of microwave/THz and infrared telescopes, and should enable detailed and quantitative models to be constructed of the planet-forming regions of circumstellar disks. This program will also push ground-based infrared spectroscopy and spectro-astrometry to their limits, and will require the optimization of data acquisition, calibration, and reduction routines to achieve a dynamic range close to that imposed by photon statistics. Such routines will be of use to a wide range of observational programs, including infrared radial velocity efforts and the characterization of extrasolar planetary atmospheres from transit measurements. At least four graduate students and several undergraduates will be trained in an exceptionally interdisciplinary manner as part of this research program. Dr. Blake's group is also highly involved in the Caltech Science for Early Educational Development and The Caltech Precollege Science Initiative K-12 educational programs, and is developing new teaching modules for a variety of grade levels.