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一起领导一个合作研究项目，该项目将利用凯克近红外光谱仪（Keck- nirspec）和甚大望远镜低温高分辨率红外梯队光谱仪（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提供了恒星形成和（外）行星科学之间的关键联系。这些圆盘的物理和化学结构，以及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。探测内部几十个天文单位（行星形成带）内的气体对于区分不同的行星形成模型是非常必要的。虽然对这些区域的气体进行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另一种途径。Blake博士和其他人最近表明，一氧化碳在4.7 μ m附近的基本旋转振动发射提供了对星周盘0.5-50 AU区域气体的广泛观察诊断。作为该提案的一部分，辐射传输工具的开发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，并将使构建星周盘行星形成区域的详细和定量模型成为可能。该项目还将把地面红外光谱和光谱天体测量推向其极限，并将需要优化数据采集、校准和缩减程序，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计划，包括红外径向速度的努力和通过凌日测量对太阳系外行星大气的表征。作为该研究项目的一部分，至少有四名研究生和几名本科生将以一种特殊的跨学科方式接受培训。Blake博士的团队还高度参与了加州理工学院早期教育发展科学和加州理工学院大学预科科学计划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.