A systematic investigation of the validity of small-body thermal models through a combined analysis of infrared and radar measurements

AST-0808064Vervack该项目将系统地研究用于确定大小和反照率信息的小天体热模型的有效性。最常见的模型通常假定为球面几何形状和小相角。红外能力方面的持续进步，包括斯皮策空间望远镜和平流层红外天文观测站，正在迅速增加观测数据，因此必须对这些假设的影响进行定量评估。该项目将通过对若干小行星的红外和雷达观测进行综合分析，调查可能存在的偏差。根据雷达观测得出的真实形状模型将被用来计算更准确的热发射模型，将基于形状的模型与最常见的热模型进行比较，可以对这些模型在尺寸和反照率估计中引入的偏差进行量化分析。特别是，这项工作将检验更逼真的形状是否会减少偏差，并将推导出更具代表性的小而不规则天体的热相函数。这项研究的影响是深远的，包括帮助适当地减轻小行星和彗星撞击地球的危险。将积极为各级学生和教师提供许多教育机会，包括参与约翰·霍普金斯大学应用物理实验室已有的指导和实习工具。阿雷西博天文台定期招收学生，并举办学生和教师研讨会。还将有机会让小型大学和学院的学生参与到大型研究项目中来，否则他们可能无法参与。

AST-0808064VervackThis project will systematically investigate the validity of the small-body thermal models used to determine size and albedo information. The commonest models generally assume a spherical geometry and small phase angles. Continued advances in infrared capabilities, including the Spitzer Space Telescope and the Stratospheric Observatory For Infrared Astronomy (SOFIA), are increasing the observational data at a rapid pace, which makes it imperative to assess quantitatively the effect of those assumptions. This project will investigate possible biases through combined analysis of infrared and radar observations of a number of asteroids. Realistic shape models derived from the radar observations will be used to calculate a more accurate thermal emission model, and comparing shape-based models to the most common thermal models provides a quantitative analysis of the biases those models introduce into the size and albedo estimates. In particular, this work will examine whether more realistic shapes will reduce the biases, and will derive a more representative thermal phase function for small, irregular bodies.The impact of this research is far reaching, including helping with proper mitigation of the hazard of Earth impact by asteroids and comets. Numerous educational opportunities for students at all levels and for teachers will be actively pursued, including involvement in mentoring and internship vehicles already in place at The Johns Hopkins University's Applied Physics Laboratory. The Arecibo Observatory regularly engages students, and conducts both student and teacher workshops. There will also be opportunities to involve students at small universities and colleges that otherwise might not get to participate in a large research project.