Collaborative Research Using High Mass Binaries to Resolve the Mass Discrepancy: Taking Things to the Extreme

使用高质量双星解决质量差异的合作研究：将事情发挥到极致

• 批准号: 0506577
• 负责人: Philip Massey
• 金额: --
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0506577&HistoricalAwards=false
• 关键词: Collaborative; Research; Using; Mass; Binaries

AST-0506577Philip MasseyLowell ObservatoryCollaborative Research Using High Mass Binaries to Resolve the MassDiscrepancy: Taking Things to the ExtremeABSTRACTAn observational program will be undertaken to determine the masses of the most massive stars.The work is motivated by significant (factors of two to three) differences in the masses of high massstars derived from evolutionary models compared with those calculated from atmosphericparameters (i.e, surface gravities from Balmer profiles combined with distance, reddening, andbolometric magnitudes). Thus, either problems remain with theories of high mass star evolution(important/unknown physical complications may have not be included), or with the spectroscopicapproach (incorrect surface gravities, luminosities, distances, etc. may be being used). To resolvethe question and ascertain the source of the discrepancy, the masses of binary O stars will bedirectly measured from an analysis of eclipsing double-lined spectroscopic binaries (specialattention will be paid to those with periods 3-5 days which have therefore not interacted). In thefirst year, young associations and clusters in the Milky Way and Magellanic Clouds will bephotometrically surveyed to find eclipsing binaries. Radial velocities for candidates will be obtainedin the second year. The third year will be used to find the orbit solutions, and to calculatespectroscopic and evolutionary masses for comparison with the results.This project includes a significant outreach and undergraduate research component. Thephotometric data (its acquisition for the northern fields and reduction for both northern and southerntargets) will be part of a key project of the National Undergraduate Research Observatory.Undergraduate students in Northern Arizona University Research Experiences for Undergraduatesprogram and MIT field camp will help with the spectroscopic observations and orbit solutions.

AST-0506577菲利普·马西·洛厄尔天文台合作研究利用大质量双星解决质量差异：把事情推向极端摘要将进行一项观测计划来确定最大质量恒星的质量。这项工作的动机是从演化模型得出的大质量恒星质量与根据大气参数计算的质量相比存在显着差异（两到三倍） （即，巴尔默剖面的表面重力与距离、红化和测辐射热强度相结合）。因此，要么是高质量恒星演化理论存在问题（可能不包括重要/未知的物理复杂性），要么是光谱方法存在问题（可能使用不正确的表面重力、光度、距离等）。为了解决这个问题并查明差异的根源，将通过对食双线光谱双星的分析来直接测量双O星的质量（将特别关注那些周期为3-5天、因此没有相互作用的双星）。第一年，将对银河系和麦哲伦云中的年轻协会和星团进行光度测量，以寻找食双星。候选人的径向速度将在第二年获得。第三年将用于寻找轨道解决方案，并计算光谱质量和演化质量，以便与结果进行比较。该项目包括重要的外展和本科生研究部分。光度数据（对北部区域的采集以及对北部和南部目标的减少）将是国家本科生研究天文台重点项目的一部分。北亚利桑那大学本科生研究经验项目和麻省理工学院野外营将有助于光谱观测和轨道解决方案。