Observation of Warm Gas in Transitional Disks around Herbig Ae/Be Stars: Interpreting their SEDs

Herbig Ae/Be 恒星周围过渡盘中温暖气体的观测：解释它们的 SED

• 批准号: 0708899
• 负责人: Sean Brittain
• 金额: $ 26.98万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0708899&HistoricalAwards=false
• 关键词: Observation; Warm; Gas; Transitional; Disks

Understanding the formation of planets remains one of astronomy''s most rewarding challenges, representing a significant component of the search for our own cosmic origins, and bearing on the possibility of life on other worlds. Although there is consensus that the evolution of gas and dust in disks around young stars is tied to planet formation, fundamental questions about this assumed coupling remain unanswered. Here, building on his previous work, Dr. Brittain will address these questions using high-resolution near-infrared spectroscopy to peer into the inner disks surrounding a class of young stars referred to as Herbig Ae/Be stars. An important tool for tracing the evolution of circumstellar disks is the measurement of the spectral energy distribution of young stars. The differences in the spectral energy distributions have led to the proposal that they reflect an evolutionary sequence from optically thick disks to transitional disks (i.e. disks with optically thick outer disks and optically thin inner disks) to optically thin disks on a timescale commensurate with planet formation. The canonical interpretation of the distinctive transitional disk morphology is that it reflects dynamical sculpting by an embedded planet. However, there are other physical effects - namely grain growth and photo-evaporation - that can give rise to transitional disks with indistinguishable spectral energy distributions. In this project the distribution of warm gas in the disks of Herbig Ae/Be stars will be observed and used to differentiate these effects via their unique signatures. Such an understanding the true origin of transitional disk morphology has fundamental implications for understanding the formation of gas-giant exoplanets and future direct imaging campaigns attempting to detect them.The undergraduate and graduate students involved with this project will have the opportunity to carry out research at one of the frontiers of modern observational astrophysics by exploiting the new partnership between the National Optical Astronomy Observatory and Clemson that provides unprecedented access to the required observing facilities - a situation conducive to launching the careers of many young scientists. Undergraduate students will be involved in this project through Clemson University''s novel Creative Inquiry initiative. This program matches teams of students with a faculty mentor for a multiyear project (typically five semesters) and provides modest funding to support their work. This work will also comprise a significant portion of a Clemson graduate student''s Ph.D. dissertation. The results of this research will be presented to the scientific community through peer-reviewed publications, colloquia, and talks at meetings as well as disseminated to the general public. This will be accomplished through continued popular presentations to the local community.

了解行星的形成仍然是天文学中最有意义的挑战之一，它代表了探索我们自己的宇宙起源的重要组成部分，并与其他世界存在生命的可能性有关。尽管人们一致认为，年轻恒星周围的气体和尘埃的演化与行星的形成有关，但关于这种假设耦合的基本问题仍未得到解答。在他之前工作的基础上，布里顿博士将利用高分辨率近红外光谱来观察一类被称为赫比格Ae/Be星的年轻恒星周围的内盘，以解决这些问题。追踪星周盘演化的一个重要工具是测量年轻恒星的光谱能量分布。光谱能量分布的差异使人们提出，它们反映了在与行星形成相称的时间尺度上从光厚盘到过渡盘（即具有光厚外盘和光薄内盘的盘）再到光薄盘的演化序列。对独特的过渡盘形态的规范解释是，它反映了嵌入行星的动态雕刻。然而，还有其他物理效应——即晶粒生长和光蒸发——可以产生具有难以区分的光谱能量分布的过渡盘。在这个项目中，热气体在赫比格Ae/Be星盘中的分布将被观察到，并通过它们独特的特征来区分这些效应。这种对过渡盘形态的真正起源的理解，对于理解气态巨行星的形成以及未来试图探测它们的直接成像活动具有根本性的意义。参与该项目的本科生和研究生将有机会通过利用国家光学天文台和克莱姆森之间的新合作伙伴关系，在现代观测天体物理学的前沿之一进行研究，这为所需的观测设施提供了前所未有的访问-这种情况有利于许多年轻科学家的职业生涯。本科生将通过克莱姆森大学的创新探究计划参与这个项目。该项目为学生团队和教师导师匹配一个多年的项目（通常是五个学期），并提供适度的资金支持他们的工作。这项工作也将包括克莱姆森研究生的博士论文的重要部分。这项研究的结果将通过同行评议的出版物、学术讨论会和会议上的演讲向科学界介绍，并向公众传播。这将通过继续向当地社区进行流行演讲来实现。