RUI: Characterizing Inner Disks in the era of JWST and ALMA

这项研究的目的是更好地了解原行星盘中的化学和物理条件，以及这些条件如何影响行星的形成和发展。该小组将检查由凯克天文台的NIRSPEC光谱仪和VLT的CRIRES光谱仪收集的现有CO排放数据。他们将开发一套新的分析工具，为两组观测中的所有原行星盘生成数据产品。他们将利用CO发射来研究圆盘内部的结构。他们还将利用ALMA观测来研究这些结构与圆盘外部部分的联系。最后，他们将研究圆盘中CO发射的可变性，并将其与嵌入原行星的潜在存在联系起来。PI机构主要是一个本科机构（PUI）。该团队预计每年约有6名本科生参与这项工作。他们还将在瓦萨学院开展一系列以观察站为基础的外展活动。高分辨率M波段（约5微米）光谱是探测盘内结构的有力工具。几乎所有围绕经典金牛座T星和赫比格Ae星的圆盘（包括内部有间隙的圆盘）都显示出CO基本振动跃迁（v= 1 - 0）的辐射，表明CO气体存在于温暖的圆盘大气中。此外，在4.6538微米处有一条H I Pf β (n = 7 - 5)发射线，它可以追踪到圆盘对恒星的吸积。利用CO发射谱线和Pf β发射谱线，以及通过分析面纱（连续谱线填充谱线）的存在，m波段光谱可以用来测量内盘尘埃边缘，因为CO在该半径内被光解离；寻找由于行星质量摄动器（嵌入的原行星）的存在而导致的线不对称或线形状变化；测量盘面大气的CO柱，或者在光学薄的情况下测量盘面本身的CO柱；来测量一些特性，比如低覆盖度圆盘的尘埃光学深度，光学厚度较薄的内盘的CO/尘埃比和吸积率，以及探测非开普勒运动的证据，比如风。该小组将开发的分析工具包括用于发射线的线通量计算器、线轮廓（形状）筛选器和线通量（板模型）筛选器。利用这些工具，该团队将为所有具有NIRSPEC和CRIRES光谱的磁盘生成CO线通量和剖面，最适合的CO温度，柱密度和发射区域，以及运动学确定的CO发射位置。这些结果将用于模拟JWST NIRSPEC仪器的观测结果，并了解原行星盘的结构。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The objective of this research is to better understand the chemical and physical conditions in protoplanetary disks, and how these conditions might influence planetary formation and development. The team will examine existing CO emission data collected by the NIRSPEC spectrometer at the Keck Observatory and the CRIRES spectrometer at the VLT. They will develop a new suite of analysis tools to produce data products for all the protoplanetary disks in the two sets of observations. They will use CO emission to study structures in the inner portions of the disks. They will also study the connection of these structures to the outer parts of the disks using ALMA observations. Lastly, they will study the variability of CO emission in disks and relate this to the potential presence of embedded protoplanets. The PI institution is a primarily undergraduate institution (PUI). The team expects to involve approximately six undergraduates per year in the work. They will also conduct a series of observatory-based outreach events at Vassar College.High-resolution M band (about 5 microns) spectroscopy is a powerful probe of inner disk structure. Nearly all disks around classical T Tauri and Herbig Ae stars (including disks with inner clearings) show emission from the CO fundamental vibrational transition (v= 1 - 0), indicative of CO gas in a warm disk atmosphere. In addition, there is an H I Pf beta (n = 7 - 5) emission line at 4.6538 microns which traces accretion of the disk onto the star. Using both the CO emission and Pf beta emission lines, as well as by analyzing the presence of veiling (infilling of spectral lines by continuum) M-band spectra can be used to measure the inner disk dust edge, as CO is photodissociated inside of that radius; to look for line asymmetries or line shape variability due to the presence of planetary mass perturbers (embedded protoplanets); to measure the CO column of the disk atmosphere, or of the disk itself if optically thin; to measure properties such as the dust optical depth for disks with low amounts of veiling the CO/dust ratio for optically thin inner disks and the accretion rate, and to detect evidence of non-Keplerian motions, such as winds. The analytic tools the team will develop include a line flux calculator for emission lines, a line profile (shape) fitter and a line flux (slab model) fitter. Using these tools, the team will produce CO line fluxes and profiles, best-fit CO temperatures, column densities and emitting areas, and kinematically-determined CO emitting locations for all of the disks with NIRSPEC and CRIRES spectra. These results will be used to model observations with the JWST NIRSPEC instrument and to understand the structures of protoplanetary disks.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.