The Dark Matter Halo Finder

我们在天空中看到的星系只是组成宇宙的物质的一小部分。绝大多数物质是“暗物质”，每个星系都是在一团巨大的暗物质中形成、生存和死亡的。因此，暗物质肯定对创造我们今天所看到的多样化的星系群产生了深远的影响。由于暗物质不是直接可见的，要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。纽约大学的科学家们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)的亮星系调查数据。作为这个项目的一部分，PI将为本科生的研究提供建议，并将这项研究的结果纳入本科课程。在这个计划中的技术是使用一个星系群探测器，它假设所有的星系群都生活在一个共同的暗物质光晕中，并且暗光晕的数量通过结构形成的数值模拟得到了很好的预测。晕的属性和形成历史取决于它们的空间分布，因此有可能通过迭代过程将观测到的星系属性映射回暗物质晕的不可观测属性，收敛到晕属性和星系属性之间的相关矩阵。这个项目将使用来自DESI明亮星系调查的新数据，几乎是SDSS光谱星表的十倍，以在我们理解暗扇区对星系形成的影响方面取得新的突破。这个奖项反映了NSF的法定使命，并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。

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.