Planning a Large-Scale Near-Infrared Survey

研究的主要内容包括对褐矮星的研究、近红外线深度巡天中恒星天体的解释以及空间红外线干涉仪成像的灵敏度分析。通过对年轻褐矮星的研究，可以清楚地看出，褐矮星既作为孤立天体形成，也作为大质量天体的伴星形成。我们分析了空间任务对棕矮星研究的潜力，发现空间任务能够探测到许多冷棕矮星，而地面观测只对暖棕矮星敏感。我们获得了冷棕矮星SDSS 1624+00的时间分辨光谱，用来研究该棕矮星的天气。虽然时间跨度短至80分钟，但我们能够探测到一些变化。小区域的深测量是对宽场测量的补充，因为深小场测量可以在微弱的量级上解释宇宙。通过构建星星计数模型，我们可以预测一般调查发现的恒星/亚恒星的人口。我们生成的模型预测了UKIRT宽视场巡天的褐矮星计数，并描绘了下一代太空望远镜看到的银河系。跟踪高角分辨率巡天发现的物体的最终仪器是空间干涉仪。空间干涉仪可以在远红外线上进行深度测量，并计算星系数量以研究宇宙学。本文首先推导了空间红外干涉仪的灵敏度公式，然后将其应用于目前计划的类地行星探测器和达尔文探测器的性能研究。我们发现辐射冷却干涉仪比冷却望远镜更灵敏，并且冷却干涉仪能够研究观测宇宙学。

Main topics of this research comprises studies of brown dwarfs, an interpretation of stellar objects in a near-infrared deep survey, and the sensitivity analysis of an imaging space infrared interferometer.From the study of young brown dwarfs, it became clear that brown dwarfs are formed both as isolated objects and as companions to more massive objects. We analyzed the potentials of space missions for brown dwarf research and found that space missions are capable of detecting many cold brown dwarfs, while ground based observations are sensitive only to warm brown dwarfs. We otained time resolved spectra of the cool brown dwarfs, SDSS 1624+00 to study weather in this brown dwarf. Although the time span was as short as 80 minutes, we were able to detect some variability.A deep survey of a small area is complementary to a wide-field survey in the sense that the deep small-field survey elucidate the universe at faint magnitudes. By constructing star count models from the data of the deep survey, we can predict stellar/substellar populations found by surveys in general. The models we generated predict the brown dwarf count of the UKIRT Wide Field Survey and depict the Galaxy seen by the Next Generation Space Telescope.The ultimate instrument to follow up objects found by a survey with high angular resolution is a space interferometer. The space interferometer can perform a deep survey in the far infrared and count galaxies to study cosmology. We first derived formulae of sensitivities of space infrared interferometers and then applied them to study the performance of currently planned Terrestrial Planet Finder and Darwin. We found that radiation cooled interferometers are more sensitive than cooled telescopes and cooled interferometers are capable of studying observational cosmology.