Precision Models for a Reference Set of Mira Variables

Mira 变量参考集的精度模型

• 批准号: 2206803
• 负责人: Michelle Creech-Eakman
• 金额: $ 52.57万
• 依托单位: New Mexico Institute of Mining and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2206803&HistoricalAwards=false
• 关键词: Precision; Models; Reference; Set; Mira

Mira variable stars are a special class of variable stars that lie at the heart of several important physical processes affecting the evolution of galaxies. They play a critical role in the galactic recycling process: over time they return much of their material to the interstellar medium and they strongly affect the appearance of galaxies. They are also extremely luminous and are excellent distance indicators, which makes them ideal candidates to map out galactic distributions. On the other hand, they are complicated stars, which can appear very differently across different wavelengths and time scales. This proposal will create the most extensive reference set of Mira variables to date, by examining a vast amount of archival data spanning several years in the past and combining them with recent observations from multiple space missions. Pairing these observations with state-of-the-art modeling tools, the team will provide a wealth of fundamental parameters for each star, such as variability periods, bolometric fluxes, radii, masses, luminosities, effective temperatures, distances. Besides the substantial direct impact on the field, the work proposed will have significant broader impacts: both the PI and Co-PI have long track-records of outreach to their local, predominantly Hispanic communities, and other members of the team are active in teaching STEM preparatory courses for young women. This study will address three fundamental questions: (1) What are the dominant pulsation modes for the various types of Miras? (2) What are the nuances in the Period-Luminosity relationship with respect to chemical subtype and mass-loss history as traced though available spectroscopic data? and (3) What is the detailed atmospheric behavior as a function of phase of molecules found at and above the photospheric surface? Most of the observations will be extracted from the Caltech-JPL’s Palomar Testbed Interferometer (PTI) using H and K bands. Periods will be determined using recent TESS data, supplemented by the long-time baseline AAVSO and AFOEV databases. The bolometric flux will be determined using 2MASS, COBE, MSX and WISE data and by custom analysis of the PTI data. Finally, distances will be determined using Gaia data. Additional photometric data will be obtained in queue mode using a dedicated, robotic 20-inch telescope. A radius-temperature modeling tool will be used to determine the additional parameters.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.

Mira变星是一类特殊的变星，它是影响星系演化的几个重要物理过程的核心。它们在星系循环过程中扮演着关键的角色：随着时间的推移，它们将大部分物质返回到星际介质中，它们强烈地影响着星系的外观。它们也非常明亮，是极好的距离指示器，这使它们成为绘制星系分布的理想候选者。另一方面，它们是复杂的恒星，在不同的波长和时间尺度上表现得非常不同。该提案将通过检查过去几年的大量档案数据，并将其与最近多次太空任务的观测结果相结合，创建迄今为止最广泛的Mira变量参考集。将这些观测结果与最先进的建模工具相结合，该团队将为每颗恒星提供丰富的基本参数，如变化周期、热通量、半径、质量、光度、有效温度、距离。除了对该领域产生重大的直接影响外，拟议的工作还将产生重大的更广泛的影响：PI和Co-PI都有长期向当地（主要是西班牙裔社区）伸出援助之手的记录，团队的其他成员也积极为年轻女性教授STEM预备课程。本研究将解决三个基本问题：(1)不同类型Miras的主要脉动模式是什么？(2)通过可用的光谱数据追踪到的化学亚型和质量损失历史，周期-光度关系的细微差别是什么？(3)在光球表面及其上方发现的分子相的详细大气行为是什么？大部分观测结果将从加州理工-喷气推进实验室的帕洛玛试验台干涉仪（PTI）中提取，使用H和K波段。周期将使用最近的TESS数据确定，并辅以长期基线AAVSO和AFOEV数据库。热通量将使用2MASS、COBE、MSX和WISE数据以及对PTI数据的定制分析来确定。最后，距离将使用盖亚数据确定。额外的光度数据将使用专用的20英寸机器人望远镜以排队模式获得。将使用半径-温度建模工具来确定附加参数。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。