Cool Dust and Gas in Transitional and Debris Disks

在这个项目中，Jonathan威廉姆斯博士（夏威夷大学）将研究星周盘在演化后期从内洞过渡到形成行星的碎片系统时的线和连续辐射。 星周盘是星星形成过程中不可避免的副产品，也是太阳系外行星的诞生地。行星本身的形成会产生额外的尘埃，这些尘埃在星星形成并沉降到主序星上很久之后才能被观察到。 在红外线中很容易检测到辐射，但辐射在光学上很厚，不能很好地测量质量，特别是在外部区域。 在亚毫米波段的观测可以确定盘的总质量。 尘埃颗粒的大小受到能量分布斜率的限制，成像定位更大的颗粒，它们受原行星引力的影响大于中心星星的辐射，线观测揭示了盘的运动学。 该计划将使用詹姆斯克拉克麦克斯韦望远镜和亚毫米阵列，亚毫米观测设施的莫纳克亚，夏威夷。除了这项研究将有助于我们理解拱星盘的演变，这项工作也将有助于教育和培训学生在亚毫米天文学和干涉测量领域。该项目将支持一名研究生的论文研究，一名本科生也将参与该项目，协助观察莫纳克亚山的运行情况，并整理观察到的磁盘上的辅助数据。这一项目及其对行星形成的影响将引起广泛的兴趣，威廉姆斯博士将继续通过在夏威夷大学天文学研究所举办的一系列外联讲座，在这一领域发表公开演讲。

In this project, Dr. Jonathan Williams (University of Hawaii) will study the line and continuum emission from circumstellar disks in the late stages of evolution, as they transition from an inner hole to a planet-forming debris system. Circumstellar disks are an inevitable by-product of star formation and the birthplaces of extrasolar planets. The formation of planets themselves generates additional dust that may be observed long after the star has formed and has settled onto the main sequence. Disks are readily detectable in the infrared but the emission is optically thick and is a poor measure of the mass, especially in the outer regions. Observations in the submillimeter regime allow total disk masses to be determined. Dust grain sizes are constrained from the slope of the energy distribution, imaging locates the larger particles that are influenced more by the gravity of a protoplanet than the radiation from the central star, and line observations reveal the disk kinematics. The program will be carried out using the James Clerk Maxwell Telescope and the Submillimeter Array, submillimeter observing facilities on Mauna Kea, Hawaii. In addition to the contribution this research will make in our understanding of the evolution of circumstellar disks, this work will also contribute to the education and training of students in areas of submillimeter astronomy and interferometry. The project will support the dissertation research of a graduate student and an undergraduate student will also participate in the project by assisting in observing runs on Mauna Kea and collating ancillary data on the observed disks. This project, with its implications for planet formation, will be of broad interest and the Dr. Williams will continue to give public talks in this field through an established outreach lecture series at the University of Hawaii's Institute for Astronomy.