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

RUI：JWST 和 ALMA 时代内盘的特征

• 批准号: 2107445
• 负责人: Colette Salyk
• 金额: $ 55.85万
• 依托单位: Vassar College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2107445&HistoricalAwards=false
• 关键词: RUI; Characterizing; Inner; Disks; era

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.

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，以及这些条件可能如何影响行星的形成和发展。该小组将检查Keck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产生数据产品。他们将使用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盘外部的联系。最后，他们将研究圆盘中CO排放的可变性，并将其与嵌入的原行星的潜在存在联系起来。私校主要是一所本科院校。该小组预计每年约有6名本科生参与这项工作。他们还将在瓦萨学院进行一系列以天文台为基础的外展活动。高分辨率M波段(约5微米)光谱是研究内盘结构的强大探测器。几乎所有围绕经典T-Tauri星和HerBig Ae星的圆盘(包括有内部间隙的圆盘)都显示出CO基态振动跃迁(v=1-0)的发射，这表明在温暖的圆盘大气中存在CO气体。此外，在4.6538微米处有一条HIPFβ(n=7-5)发射线，它跟踪了圆盘对恒星的吸积。使用CO发射线和Pfβ发射线，以及通过分析面纱的存在(谱线的连续填充)，M波段光谱可用于测量内盘尘埃边缘，因为CO在该半径内被光解离；寻找由于行星质量微扰(嵌入的原行星)的存在而引起的线不对称或线形变化；测量盘大气的CO柱，或如果光学较薄，则测量盘本身的CO柱；测量具有低遮盖量的圆盘的尘埃光学厚度、光学薄内盘的CO/尘埃比和吸积率等性质，并检测非开普勒式运动的证据，例如风。该团队将开发的分析工具包括排放管线的管线流量计算器、管线轮廓(形状)拟合工具和管线通量(平板模型)拟合工具。使用这些工具，该团队将为所有具有NIRSpec和CRIRES光谱的圆盘生成CO线通量和轮廓、最佳匹配的CO温度、柱密度和发射区域，以及以运动学方式确定的CO发射位置。这些结果将用于JWST NIRSpec仪器的观测建模和了解原行星盘的结构。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。