The Physical Properties of Hot and Cool Massive Stars as a Function of Metallicity in the Local Group

这项工作的动机是需要不同金属丰度的大质量恒星的准确物理性质，以便了解它们的演化、恒星形成过程和反馈到星际介质的机制。特别值得关注的是温度，它在将观测数据(光谱类型和测光)转换为物理性质(有效温度、表面重力、测辐射热光度、半径和推断质量)方面起着关键作用。在这个项目中，将改进热(30,000到50,000 K)主序和冷(3,000到4,000 K)演化(红超巨星)大质量恒星的有效温度尺度。这将使用高质量的光学光谱(在冷巨星的情况下加上红外测光)和最新一代恒星大气模型在这两个温度极端下完成。特别重要的是，这些定标将作为金属丰度的函数而发展，因此适用于整个本地区群中大质量恒星的其他研究。本科生将通过NSF资助的本科生研究经验和麻省理工学院野战营计划参与这项工作。这些学生将成为完全的合作者，并参与数据采集、分析、写作和在科学会议上展示结果。这项研究还将通过洛厄尔天文台访客计划和其他场所的公开演讲进行。收集到的数据一旦被接受发布，也将被公开。

This work here is motivated by the need for accurate physical properties of massive starsof varying metallicity in order to understand their evolution, star formation processes, andfeedback mechanisms into the interstellar medium. Of particular interest is temperature,which plays a key role in transforming observations (spectral type and photometry) intophysical properties (effective temperature, surface gravity, bolometric luminosity, radius,and inferred mass). In this project, an improvement of the effective temperature scales forboth hot (30,000 to 50,000K) main-sequence and cool (3,000 to 4000K) evolved (redsupergiant) massive stars will be undertaken This will be accomplished using high qualityoptical spectra (plus infrared photometry in the case of the cool giants) and the latestgeneration of stellar atmosphere models at both temperature extremes. Of particularimportance is that these calibrations will be developed as a function of metallicity andtherefore applicable to other studies of high mass stars throughout the local group.Undergraduate students will be involved in this work through the NSF sponsoredResearch Experiences for Undergraduates and MIT Field Camp programs. The studentswill be full collaborators and take part in data acquisition, analysis, writing, and thepresentation of results at scientific meetings. This research will also be featured in publictalks given through the Lowell Observatory visitor program and at other venues. The datacollected here will also be made public once accepted for publication.