Research in Infrared and Millimeter Astronomy

最近仪器技术的进步使天文学家第一次看到了年轻恒星形成的痕迹，即“金牛座T”恒星周围的星周盘。对这些圆盘及其中心恒星的研究有望为我们太阳系的早期演化提供基本的见解。首席研究员（PI）将继续之前的研究，他使用红外和毫米波长的中间阵列来解析两颗金牛座T星周围的圆盘，包括质量与木星相似的物质团块。在这个更新计划中，PI将把他的研究扩展到更暗的亮度，因此将能够研究统计上稳定的年轻恒星样本。目标是了解恒星的哪些特性会影响磁盘的特性，并研究磁盘如何在逐渐变老的恒星的子样本中演变。一个关键的问题将是确定一颗恒星在“双星”中的重要性（一对恒星在同一时间出生并围绕彼此运行）。目前的观点认为，一颗紧密的双星的存在会把恒星上的物质扫走，从而阻止圆盘的形成，从而阻止行星系统的形成。PI将测试早期的迹象，即紧密间隔的二进制文件没有磁盘，而单个或大间隔的二进制文件有磁盘。PI还将把他的观测和数据简化技术扩展到对银河系中心的红外毫米研究，以及由外部星系碰撞产生的星际气体冲击。

Recent advances in instrument technology have allowed astronomers their first glimpses of the vestiges of young star formation, circumstellar disks around "T Tauri" stars. A study of both these disks and their central stars is expected to provide fundamental insights into the early evolution of our own solar system. The Principle Investigator (PI) will continue previous research in which he has used infrared and millimeter wavelength interometer arrays to resolve the disk around two T Tauri stars, including clumps of material having masses similar to the planet Jupiter's. In this renewal program the PI will extend his studies to fainter brightnesses and hence will be able to study a statistically stable sample of young stars. The goals are to understand which properties of stars influence disk properties and to examine how the disks evolve in subsamples of progressively older stars. A key question will be to identify the importance of a star's being in a "binary" (a pair of stars born at the same time and orbiting around one another). Current ideas hold that the presence of a close binary star will sweep away the matter from a star and prevent the formation of a disk and hence a system of planets. The PI will test early indications that closely-spaced binaries do not have disks and that single or widely-spaced binaries do. The PI will also extend his observational and data reduction techniques to the infrared-millimeter study of the center of our Galaxy, as well as to shocks in interstellar gas created by the collisions of external galaxies.