Survey Cosmology

这笔滚动赠款是为了支持朴茨茅斯大学宇宙学与引力研究所(ICG)的新的观测宇宙学小组。ICG成立于2002年，但在该大学以及英国和欧洲的资助机构的战略投资的推动下，ICG取得了快速增长。ICG目前共有来自世界各地的10名工作人员、11名博士后研究人员和17名博士生，从事理论和观测宇宙学方面的工作。在新技术和新理论的推动下，宇宙学正在经历一个发现的黄金时代。然而，在实现完整的宇宙理论之前，我们仍然面临着两个根本性的挑战：i)构成宇宙96%的暗物质和暗能量的性质是什么；ii)星系--宇宙的“基石”--是如何形成和演化的？这笔滚动拨款将通过使用新的大规模天空调查来解决这两个问题。例如，我们将在智利的Blanco 4米望远镜上使用一台新的5.2亿像素相机来数字拍摄南方天空。这项被称为暗能量调查(DES)的调查将使我们能够高精度地测量星系团，探测前景暗物质对遥远星系的弱引力透镜，并发现数千颗遥远的超新星(正在爆炸的恒星)。结合斯隆数字巡天和其他数据，我们预计将测量宇宙年龄的70%以上的暗能量密度。这将告诉我们，它是像爱因斯坦最先提出的那样只是一个常量，还是更奇特的东西，比如精华、幻影能量或额外的维度！这些数据还将揭示暗物质的性质，我们可以通过重力“看到”暗物质，但它不像正常物质那样发光。除了新的光学相机，我们还计划利用正在建造的下一代射电望远镜的动力。其中第一个是LOFAR，它将在欧洲各地建立基站，形成一个大小超过600公里的有效射电望远镜。我们将利用LOFAR，结合SDSS的新数据，研究超大质量黑洞对椭圆星系演化的影响。从这些黑洞流出的能量被认为是减缓此类星系增长的一种方式，使它们今天变得“红色和死亡”。同样，我们将研究具有宇宙时间和位置的盘状星系的性质，以确定是什么促使它们在今天形成新的恒星。总之，这些研究将帮助我们确定驱动星系演化的重要物理因素。除了研究，ICG的工作人员还致力于向世界公布他们的数据。我们计划继续这项工作，为科学界提供使用最新网络服务技术的最先进数据档案。国际协调小组的工作人员还致力于公共宣传，并在媒体和当地学校开展了一些显眼的活动。例如，我们的学生和博士后访问了当地的学校，讨论他们的职业生涯，表达做研究的乐趣。最后，ICG是一个紧密联系的社区，为学生和教师的培训和指导提供强大的支持基础设施。

This rolling grant is to support the new observational cosmology group at the Institute of Cosmology and Gravitation (ICG) at the University of Portsmouth. The ICG was only formed in 2002 but has seen rapid growth, driven by strategic investments by the university and funding agencies in the UK and Europe. In total, the ICG now has 10 staff members, 11 postdoctoral researchers, and 17 PhD students from around the world, working on both theoretical and observational cosmology. Cosmology is experiencing a golden age of discovery driven by new advances in technology and theory. However, we are still facing two fundamental challenges before a complete theory of the Universe can be achieved: i) What are the properties of the dark matter and dark energy that make up 96% of the Universe, and ii) how do galaxies - the 'building blocks' of the Universe - form and evolve? This rolling grant will address both these problems through the use of new, massive surveys of the sky. For example, we will use a new 520-megapixel camera on the Blanco 4-meter telescope in Chile to digitally image the southern sky. This survey - known as the Dark Energy Survey (DES) - will allow us to measure the clustering of galaxies to high precision, detect the weak gravitational lensing of distant galaxies by the foreground dark matter, and discover thousands of distant supernovae (exploding stars). Taken together with the Sloan Digital Sky Survey and other data, we expect to measure the density of dark energy over 70% the age of the Universe. This will tell us if it is just a constant, as first proposed by Einstein, or something more exotic like quintessence, phantom energy or extra dimensions! This data will also shed light on the properties of dark matter, which we can 'see' via gravity but does not shine like normal matter. In addition to new optical cameras, we plan to harness the power of the next generation of radio telescopes that are being built. The first of these is LOFAR, which will have base stations spread across Europe forming an effective radio telescope over 600 kilometers in size. We will use LOFAR, in conjunction with new data from the SDSS, to study the effects of supermassive black holes on the evolution of elliptical galaxies. The energetic outflows from these black holes has been proposed as a way to slowing down the growth of such galaxies, making them 'red and dead' today. Likewise, we will study the properties of disk galaxies with cosmic time and location to determine what is encouraging them to form new stars today. Together, these studies will help us determine the important physics that drive galaxy evolution. In addition to research, the ICG staff are dedicated to publishing their data to the world. We plan to continue this work by providing the scientific community with access to state-of-the-art data archives using the latest web-services technology. The ICG staff are also committed to public outreach and have been engaged in a number of visible activities in the media and local schools. For example, our students and postdocs have visited local schools to discuss their careers and express the fun of doing research. Finally, the ICG is a close-knit community that provides a strong support infrastructure for the training and mentoring of students and faculty alike.