Observations with Infrared Space Observatory (ISO)

该项目旨在通过国际联合研究，利用红外空间天文台（ISO）上的液氦冷却空间望远镜，寻找形成星系和研究恒星最后演化阶段的物理学。我们的ISO观测包括(1)在Lockman洞的ISO深红外巡天，以寻找在光学巡天中可能错过的形成星系；(2)对麦哲伦星云中星团中心部分的ISO多色成像，以研究非常晚期恒星的质量损失；(3)发射谱线的光谱映射，以探测年轻热恒星附近的光电离结构。为了实现上述目标，我们必须通过检查ISO数据进行校准，了解ISO仪器在太空中的特性，并在地面进行后续观测。我们被允许派六名科学家去法国分析ISO仪器的特性。因此，我们现在比以前更好地了解ISO工具及其行为，为减少数据提供了坚实的基础。因此，我们几乎完成了数据缩减，特别是ISO深红外测量项目。最初计划进行KPNO和IRAM的后续观察。随后，为了寻找更好的观测设备，合作者们做出了努力，使得加州理工学院亚毫米天文台的10米亚毫米望远镜和夏威夷大学的2.2米光学望远镜得以使用，这两个望远镜都位于美国夏威夷的莫纳克亚天文台。后续观察工作刚刚开始，将在今后几个月继续进行。在这个项目中，我们发现(1)ISO远红外源的表面密度比非演化模型的预期高10倍；(2)非常晚的恒星富含分子和尘埃，这是任何现有的恒星大气模型都无法解释的。

This project intends to search for forming galaxies and investigate physics at the last evolutionary stage of stars by using the liquid-helium-cooled space telescope onboard the Infrared Space Observatory (ISO) via international joint research. Our ISO observations include (1) ISO deep infrared survey in the Lockman Hole to search for forming galaxies which might have been missed in the optical surveys, (2) ISO multicolor imaging of central parts of star clusters in the Magellanic Clouds to study mass-loss of very-late stars, and (3) spectroscopic mapping of emission lines to probe the photo-ionized structure near young hot stars.To achieve the above objectives, we had to understand the characteristics of the ISO instrument in space through examining ISO data taken for calibration, and carry out follow-up observations from the ground.We were allowed to send six scientists to France to analyze the characteristics of the ISO instrument. As a result, we now understand the ISO instrument and their behavior much better than before, providing the firm basis for reducing data. Accordingly, we have almost completed the data reduction, which is especially true to the ISO deep infrared survey project.Follow-up observations were initally planned to carry out KPNO and IRAM.Subsequent efforts made by collaborators for seeking better observing facilities made it possible to use the 10m sub-millimeter telescope in the Caltech Sub-millimeter Observatory and the 2.2m optical telescope of the University of Hawaii, both located in the Mauna Kea Observatory, Hawaii, USA.The follow-up observations have just started, which will be continued for the next several months.During this project, we found (1) the surface density of ISO far-infrared sources is 10 times higher than expected from the non-evolution model, and (2) very late stars are rich in molecules and dust which cannot be explained by any existing models of stellar atmosphere.