Molecular Hydrogen Emission from the Disks of T Tauri Stars

这是一个对年轻的T-Tauri类型恒星进行调查的项目，目的是确定是否存在证据表明，在超过纪元的时候，当亚毫米热发射和毫米线发射中看到的那些盘的特征消失时，它们的星周盘仍然存在。具体地说，研究人员正在使用非常灵敏的高光谱分辨率光谱仪对分子氢进行红外测量，主要是在双子座南方望远镜和英国红外望远镜上。几年的前期工作结果证明了探测T-Tauri恒星周围未受激波的氢的谱线发射的可行性。以前的结果与氢发射的预期亮度一致，从线形来看，明确地表明，对于一颗恒星，和其他恒星一样，线辐射是来自圆盘中间层的气体，距离恒星10到30个天文单位(地球-太阳距离)。对几个恒星形成区域中大多数T-Tauri恒星的氢线发射的调查将有助于更清楚地了解类太阳主序前恒星周围的圆盘通常是在行星形成之前分散，还是在最初的1000万年内向小行星和行星演化。所有数据将以简化的、自我校准的光谱的在线可搜索数据库的形式向公众提供。该项目的网址还将包括专门用于教育和公众宣传的网页，包括关于光谱学在理解恒星和行星形成过程中的作用的解释材料。首席研究员积极致力于将天文学带给纳什维尔大都市地区的教师和学生。他是一个名为“探索我们的太阳邻居”的新项目的合作伙伴，该项目将通过教师培训研讨会和学生指导为教师和学生带来天文学内容。作为这些项目的一部分，包括为15名教师举办的为期一周的暑期学院，以及在暑期和学年与学生进行的后续活动，首席研究员将教授有关行星以及行星形成过程的知识，从而将该项目的尖端知识和研究直接带给教师和未来潜在的科学家。这通常包括本科生，特别是范德比尔特大学名为科学与技术传播学专业的本科生，参与该项目的研究活动。

AST 0307416PI WeintraubThis is a project to conduct a survey of the young T Tauri-type stars to ascertain whether evidence exists for the continued presence of their circumstellar disks at times beyond the epoch when the signatures of those disks as seen in submillimeter thermal emission and millimeter line emission have disappeared. Specifically, the researchers are carrying out an infrared survey of molecular hydrogen using very sensitive, high spectral resolution spectrometers primarily on the Gemini South telescope and the United Kingdom Infrared Telescope. Results from several years of preliminary work demonstrate the feasibility of detecting line emission from unshocked hydrogen around T Tauri stars. Previous results are consistent with the expected brightnesses of hydrogen emission and from the line shapes, it is shown definitively for one star and as likely for other stars, that the line emission is from gas in the middle layers of disks and from distances of 10 to 30 Astronomical Units (the earth-Sun distance) from the stars. A survey of hydrogen line emission from most of the T Tauri stars in several star forming regions will make an important contribution to developing a clearer understanding as to whether disks around Sun-like pre-main-sequence stars typically disperse prior to planet building or evolve toward planetesimals and planets within the first 10 million years.Broader Impact. All data will be made available to the public in the form of an on-line, searchable database of reduced, self-calibrated spectra. Also included on this project internet site will be web pages devoted to education and public outreach, including explanatory material concerning the role of spectroscopy in understanding the processes of star and planet formation. The Principle Investigator is actively engaged in bringing astronomy to teachers and students in the metropolitan Nashville area. He is a partner in a new program, "Exploring our Solar Neighborhood," which will bring astronomy content to teachers and students through teacher training workshops and student instruction. As part of these programs, which include a weeklong Summer Institute for 15 teachers and follow-up activities during the summer and school year with their students, the Principle Investigator will teach about the planets and about the processes by which planets form, thus bringing cutting edge knowledge and research from this program directly to teachers and potential future scientists. This regularly includes undergraduate students, especially those in a unique undergraduate major at Vanderbilt University called the Communication of Science and Technology, in the research activities of this project.