Collaborative Research: Taking Measure of the Universe with Galaxy and Cluster Surveys

AST-0708490/AST-0708539 Gonzalez/Mohr这个项目将使用星系团调查和星系团观测，对宇宙的膨胀历史进行一系列逐步更精确的测量。该小组将利用斯皮策空间望远镜完成和描述两项多波段光学和红外星系团调查，即使用斯皮策空间望远镜的IRAC浅层星系团调查(ISCS)和使用智利的布兰科4米望远镜的布兰科宇宙学调查(BCS)。BCS将被用来测量星系的功率谱，其中350万个星系的红移大于1。这些新计划将与目前和即将进行的毫米波探测相协调，这些毫米波探测旨在利用Sunyaev-Zel‘dovich效应发现星团。未来旨在对暗能量状态方程施加限制的调查将总是受到系统性不确定性的限制，而不是统计不确定性。ISCS和BCS将澄清和量化这些系统效应，同时获得新的、近期的宇宙学限制。该工作使用星表和集群模拟来精确地估计调查的完整性和污染度，以及集群质量估计的准确性。它还侧重于具有光学/红外和毫米波数据的领域，无论是现在还是将来，以及一些现有的X射线数据。多波长方法能够交叉校准领先的星系团选择方法，开发更清洁和更灵敏的选择技术的可能性，并直接测试选择模型。这个项目将对正在进行和即将进行的更大规模的实验产生重大影响。由于BCS将构成南半球最大的连续深部光学调查，由此产生的公共数据集将对许多其他应用具有重要价值，例如星系演化研究。该小组有与K-12教师和学生合作的记录，并将结合本研究扩大这一工作。

AST-0708490/AST-0708539Gonzalez/MohrThis project will execute a series of progressively more precise measurements of the expansion history of the Universe using galaxy cluster surveys and the clustering of galaxies. This team will complete and characterize two multi-band optical and infrared cluster surveys, the IRAC Shallow Cluster Survey (ISCS), using the Spitzer Space Telescope, and the Blanco Cosmology Survey (BCS), using the Blanco 4m telescope in Chile. The BCS will be used to measure the galaxy power spectrum with 3.5 million galaxies extending to redshifts greater than one. These new programs will be coordinated with current and forthcoming millimeter-wave surveys designed to find clusters using the Sunyaev-Zel'dovich effect. Future surveys intended to deliver constraints on the dark energy equation of state will invariably be limited by systematic rather than statistical uncertainties. The ISCS and BCS will clarify and quantify these systematic effects, while simultaneously obtaining new, near-term cosmological constraints. The work uses catalog and cluster simulations to estimate precisely the survey completeness and contamination, and the cluster mass estimate accuracy. It also focuses on fields with optical/infrared and mm-wave data, now or soon, and with some existing X-ray data. The multi-wavelength approach enables a cross-calibration of the leading cluster selection methods, the possibility of developing cleaner and more sensitive selection techniques, and direct tests of the selection models.This project will significantly impact larger experiments under way and to come. Because the BCS will constitute the largest contiguous deep optical survey in the southern hemisphere, the resulting public data set will be of great value for numerous other applications, such as galaxy evolution studies. This team has a record of working with K-12 teachers and students, and will expand that work in conjunction with the present research.