The Dark Matter Halo Finder

我们在天空中看到的星系只是构成宇宙物质的一小部分。绝大多数物质都是“暗物质”，每个星系都是在一团暗物质中形成、生存和死亡的。因此，暗物质一定对我们今天看到的各种星系的形成产生了深远的影响。由于暗物质不能直接观测到，理解这种影响需要新的方法来间接测量暗物质和我们所看到的星系之间的联系。纽约大学的科学家将开发一种新的统计方法来量化这种关系，并将其应用于暗能量光谱仪器（DESI）的明亮星系调查数据。作为该项目的一部分，PI将为本科生提供研究建议，并将研究结果纳入本科课程。这项提议中的技术是使用一个星系群发现者，假设所有星系群都生活在一个共同的暗物质晕中，并且通过结构形成的数值模拟可以很好地预测暗晕的数量。晕的性质和形成历史取决于它们的空间分布，因此可以通过迭代过程将观测到的星系性质映射回暗物质晕的不可观测性质，收敛于晕性质与星系性质之间的相关矩阵。这个项目将使用来自DESI明亮星系调查的新数据，它几乎是SDSS光谱目录的十倍，在我们对暗扇区对星系形成的影响的理解上开辟了新的领域。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。

The galaxies we see in the sky are only a small part of the material that makes up the universe. The vast majority of matter is “dark matter,” and each galaxy forms, lives, and dies in a massive clump of dark matter. Thus, the dark matter must have a profound influence on creating the diverse population of galaxies that we see today. Since dark matter isn’t directly observable, understanding this influence requires new methods to indirectly measure the connection between the dark matter and the galaxies that we see. Scientists at New York University will develop a new statistical method for quantifying this relationship and will apply it to data from the Bright Galaxy Survey of the Dark Energy Spectroscopic Instrument (DESI). As part of this project, the PI will advise undergraduate students in research and will incorporate results from this research into undergraduate coursework.The technique in this proposal is to use a galaxy group finder that assumes that all groups live in a common dark matter halo, and that the population of dark halos is well-predicted by numerical simulations of structure formation. The properties and formation histories of halos is imparted on their spatial distribution, thus it is possible to map the observed properties of galaxies back onto the unobservable properties of dark matter halos in an iterative process, converging on a correlation matrix between halo properties and galaxy properties. This project will use new data from the DESI Bright Galaxy Survey, nearly a factor of ten larger than the SDSS spectroscopic catalog, to break new ground in our understanding of the influence of the dark sector on galaxy formation.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.