Galaxy intrinsic alignments: A new window into structure in the Universe

对星系的观测可以用来绘制宇宙的结构图，并探索物理学中一些最大的奥秘，包括“暗物质”和“暗能量”。包括新的大望远镜和科学家的大规模合作在内的即将到来的努力将观察数十亿个星系。为了利用这些令人印象深刻的数据集，了解星系的属性，特别是它们的形状，与周围环境的关系是至关重要的。东北大学的科学家将使用最先进的观测和理论计算机模拟来发展对星系形状的理解。这些进展将使对基本宇宙学模型的更准确研究成为可能，这是科学界的一个关键目标。通过研究机会和有针对性的指导，该项目还将推进物理和天文学方面的本科生培训，特别关注第一代、无证学生和低收入(FUNL)学生。星系“内禀排列”(IA)是一种重要的天体物理效应，其中星系的内禀形状与宇宙中的大尺度结构有关。这一效应影响了涉及弱引力透镜和星系团的分析，包括使用即将到来的维拉·C·鲁宾天文台的数据进行的计划中的关键研究。IA必须足够好地理解，以便能够对宇宙模型进行既准确又精确的测试。这个项目将通过一个有针对性的观察和新颖、高效的模拟技术的连贯计划，显著提高对IA的理解。利用暗能量调查的最终数据集，该团队将采用几种旨在探索不同制度下的IA的战略，通过一个单一的分析框架统一起来。通过这些测量，具有真实IA的模拟星系将从仅限重力的模拟中产生，从而避免了流体动力学模拟的计算挑战，并允许产生大宇宙体积和具有广泛的IA属性的模拟星系星表。从这些努力中获得的洞察力将使在未来的分析中大大提高缓解IA的能力。此外，该团队将利用他们的结果和模拟能力，利用下一代数据开发IA作为天体物理学和宇宙学的探测器。这一奖项反映了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。

Observations of galaxies can be used to map out structure in the Universe and probe some of the greatest mysteries in physics, including “dark matter” and “dark energy.” Upcoming efforts that involve new big telescopes and large collaborations of scientists will observe billions of galaxies. To harness these impressive data sets, it is essential to understand how galaxy properties, especially their shapes, relate to their surrounding environment. Scientists at Northeastern University will use state-of-the-art observations as well as theoretical computer simulations to develop the understanding of galaxy shapes. These advances will enable more accurate studies of the underlying cosmological model, a key goal of the scientific community. Through research opportunities and targeted mentoring, this project will also advance undergraduate training in physics and astronomy, with a particular focus on first-generation, undocumented, and low-income (FUNL) students. Galaxy “intrinsic alignments” (IA) are an important astrophysical effect in which the intrinsic shapes of galaxies are correlated with large-scale structure in the Universe. This effect impacts analyses that involve weak gravitational lensing and galaxy clustering, including planned key studies using data from the upcoming Vera C. Rubin Observatory. IA must be sufficiently well understood to allow tests of the cosmological model that are both accurate and precise. This project will significantly improve the understanding of IA through a coherent program of targeted observations and novel, efficient simulation techniques. Using the final data set of the Dark Energy Survey, the team will employ several strategies designed to probe IA in different regimes, unified through a single analysis framework. Informed by these measurements, simulated galaxies with realistic IA will be produced from gravity-only simulations, avoiding the computational challenges of hydrodynamic simulations, and allowing the production of mock galaxy catalogs in large cosmological volumes and with a wide range of IA properties. The insights from these efforts will enable a substantial improvement in the ability to mitigate IA in future analyses. In addition, the team will use their results and simulation capabilities to develop IA as a probe of astrophysics and cosmology with next-generation data.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.