Are Hubble Residuals a Product of Poor Mass Estimates? Improving Supernova Ia Host Galaxy Characterizations

哈勃残差是质量估计不佳的产物吗？

• 批准号: 2205635
• 负责人: Louis-Gregory Strolger
• 金额: $ 35.57万
• 依托单位: Johns Hopkins University
• 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: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2205635&HistoricalAwards=false
• 关键词: Hubble; Residuals; Product; Poor; Mass

Type Ia supernovae (SNIa) are extraordinary cosmological distance indicators that were used in the discovery of the accelerated expansion of the universe and are now being used for precision measurements of the equation of state of dark energy. SNIa properties now curiously show trends with host galaxy properties, which complicates their use as clean predictors of distance. At present, it is not clear if these trends are indicating something physical, or if they are simply a manifestation of insufficient data and the methods that are used to measure galaxy properties. This project will revisit these trends, making use of the more extensive multi-wavelength datasets that are now available, and improved methods for characterizing galaxy masses and other properties. The team at Johns Hopkins University will enlist undergraduate interns from Baltimore-area schools, with a focus on students from underrepresented and underserved backgrounds, to participate in the archival data recovery, galaxy characterization, and publication of the final catalogs.The main goal of this program is to test the much-debated existence and magnitude of Hubble residuals, excesses in corrected SNIa peak luminosities that appear to correlate with host galaxy masses. The team will compile an extensive multi-wavelength dataset from available and soon to be available infrared archives, leveraging existing optical data to recover the best available star-formation histories from non-parametric fitting, and more accurately determine stellar masses and star-formation rates for SNIa host galaxies from the Pantheon+ sample, which is a large compilation of several past SNIa surveys. Using this complete and robust catalog of host characteristics, the team will revisit Hubble residuals and their implications for cosmological analyses. In addition, this project will allow the first estimation of SNIa delay-time distributions as a function of host mass, and over a wide redshift range, and thus test the hypothesis, implied by the Hubble residuals, that SNIa are the products of more than one dominant progenitor mechanism.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.

Ia型超新星（SNIa）是非凡的宇宙距离指示器，用于发现宇宙的加速膨胀，现在被用于暗能量状态方程的精确测量。SNIa的性质现在奇怪地显示出与宿主星系性质的趋势，这使得它们作为距离预测器的使用变得复杂。目前，尚不清楚这些趋势是否表明了一些物理上的东西，或者它们仅仅是数据不足和用于测量星系特性的方法的表现。这个项目将重新审视这些趋势，利用现在可用的更广泛的多波长数据集，以及改进的表征星系质量和其他特性的方法。约翰霍普金斯大学的团队将从巴尔的摩地区的学校招募本科生实习生，重点关注来自代表性不足和服务不足背景的学生，参与档案数据恢复，星系特征描述和最终目录的出版。这个项目的主要目标是测试哈勃残差的存在和大小，校正后的SNIa峰值亮度的过剩似乎与宿主星系的质量有关。该团队将从现有的和即将可用的红外档案中编译一个广泛的多波长数据集，利用现有的光学数据从非参数拟合中恢复最佳可用的恒星形成历史，并更准确地确定Pantheon+样本中SNIa宿主星系的恒星质量和恒星形成率，这是过去几次SNIa调查的大型汇编。利用这个完整而可靠的宿主特征目录，研究小组将重新审视哈勃残差及其对宇宙学分析的影响。此外，该项目将允许首次估计SNIa延迟时间分布作为宿主质量的函数，并且在很宽的红移范围内，从而验证哈勃残差所暗示的假设，即SNIa是多个主导祖先机制的产物。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。