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

了解行星的形成仍然是天文学最有价值的挑战之一，代表着寻找我们自己的宇宙起源的重要组成部分，并关系到其他星球上存在生命的可能性。尽管人们一致认为年轻恒星周围圆盘中气体和尘埃的演化与行星的形成有关，但有关这种假设耦合的基本问题仍未得到解答。在这里，布里顿博士将在他之前的工作基础上解决这些问题，利用高分辨率近红外光谱来观察一类被称为 Herbig Ae/Be 恒星的年轻恒星周围的内盘。 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导致有人提出，它们反映了在与行星形成相称的时间尺度上从光学厚盘到过渡盘（即具有光学厚外盘和光学薄内盘的盘）到光学薄盘的演化序列。对独特的过渡盘形态的规范解释是，它反映了嵌入式行星的动态塑造。然而，还有其他物理效应，即晶粒生长和光蒸发，可能会产生具有难以区分的光谱能量分布的过渡盘。 在该项目中，将观测 Herbig Ae/Be 恒星盘中温暖气体的分布，并通过其独特的特征来区分这些效应。了解过渡盘形态的真正起源对于理解气态巨系外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意义。参与该项目的本科生和研究生将有机会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开展研究，该伙伴关系提供了前所未有的所需观测设施 - 这种情况有利于许多年轻科学家开启职业生涯。本科生将通过克莱姆森大学新颖的创意探究计划参与该项目。该计划将学生团队与导师进行多年项目（通常为五个学期）的匹配，并提供适度的资金来支持他们的工作。这项工作也将构成克莱姆森研究生博士学位的重要组成部分。论文。这项研究的结果将通过同行评审的出版物、座谈会和会议演讲向科学界展示，并向公众传播。这将通过持续向当地社区进行受欢迎的演示来实现。

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.