Securing the Foundation of the IR-TRGB Distance Ladder

确保 IR-TRGB 距离梯的基础

• 批准号: 2108616
• 负责人: Rachael Beaton
• 金额: $ 34.62万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108616&HistoricalAwards=false
• 关键词: Securing; Foundation; IR; TRGB; Distance

The expansion rate of the universe, also known at the Hubble constant, is measured both from a distance scale and from the Cosmic Microwave Background. These two methods give different values. It is possible that systematic errors cause these different values, so independent techniques for the measurement of the Hubble constant need to be developed. The infrared tip of the red giant branch method (IR-TRGB) could be a powerful tool to probe large volumes and a wider set of Type Ia supernova galaxy hosts. However, the IR-TRGB method needs proper calibration, which requires new ground-based observations. This project will develop new tools for the IR-TRGP measurement. Ongoing projects, in collaboration with minority serving institutions, that provide research opportunities for undergraduate students will be enhanced with these tools. A sibling robotic optical telescope with time allocated for E/PO efforts will be made accessible to outreach via the creation of supporting materials and a wide range of E/PO education modes for both classrooms and informal settings.This project will provide two anchor points to a distance scale built on the IR-TRGB and seamlessly connect these anchor points to IR-TRGB measurements made with space-based facilities. The IR-TRGB has the intrinsic brightness and efficient application to measure distances for statistical samples of SN Ia hosts. The team will: (1) Complete the implementation a fully-robotic, dual channel optical/infrared facility capable of monitoring bright stars in the infrared and publish design specifications and operational data for the facility. (2) Use this facility to produce photometry of key calibrations for the IR-TRGB in the Milky Way and LMC. (3) With an on-going HST program, derive or predict filter transformations between ground- and space-based filter systems that enable the IR-TRGB. (4) Calibrate the absolute magnitude-color behavior of the IR-TRGB in two anchor objects with high precision geometric distances (Milky Way Field and LMC).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.

宇宙的膨胀率，也称为哈勃常数，既可以从距离尺度上测量，也可以从宇宙微波背景中测量。这两种方法给出的值不同。有可能是系统误差导致了这些不同的值，因此需要开发独立的哈勃常数测量技术。红巨星分支法的红外线尖端(IR-TRGB)可能是探测大体积和更广泛的Ia型超新星星系主机的有力工具。然而，IR-TRGB方法需要适当的校准，这需要新的地面观测。该项目将为IR-TRGP测量开发新的工具。与少数群体服务机构合作，为本科生提供研究机会的正在进行的项目将利用这些工具得到加强。将通过为教室和非正式场所创建辅助材料和广泛的E/PO教育模式，向外展人员提供分配时间用于E/PO工作的兄弟机器人光学望远镜。该项目将在IR-TRGB的基础上提供两个距离比例尺的锚点，并将这些锚点与利用天基设施进行的IR-TRGB测量无缝连接。IR-TRGB具有固有的亮度和有效的应用，用于测量统计样本的SN Ia主机的距离。该小组将：(1)完成全机器人、双通道光学/红外设施的实施，该设施能够监测红外中的明亮恒星，并公布该设施的设计规格和运行数据。(2)利用该设施生产用于银河系和LMC的IR-TRGB的关键校准的光度测量。(3)使用正在进行的HST程序，推导或预测实现IR-TRGB的陆基和天基滤波系统之间的滤波变换。(4)校准IR-TRGB在两个具有高精度几何距离的锚定对象(银河场和LMC)上的绝对星等-颜色行为。该奖项反映了NSF的法定使命，并已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。

项目成果

CATS: The Hubble Constant from Standardized TRGB and Type Ia Supernova Measurements

• DOI: 10.3847/2041-8213/ace978
• 发表时间: 2023-04
• 期刊: The Astrophysical Journal Letters
• 作者: D. Scolnic;A. Riess;J. Wu;S. Li;G. Anand;R. Beaton;S. Casertano;R. Anderson;S. Dhawan;X. Ke

Standardized Luminosity of the Tip of the Red Giant Branch Utilizing Multiple Fields in NGC 4258 and the CATs Algorithm

利用 NGC 4258 中的多个场和 CAT 算法对红巨星分支尖端的标准化光度

• DOI: 10.3847/1538-4357/acf4fb
• 发表时间: 2023
• 期刊: The Astrophysical Journal
• 作者: Li, Siyang;Riess, Adam G.;Scolnic, Daniel;Anand, Gagandeep S.;Wu, Jiaxi;Casertano, Stefano;Yuan, Wenlong;Beaton, Rachael;Anderson, Richard I.
• 通讯作者: Anderson, Richard I.