Dark Energy Survey: Year 3 Observing Shift

以下摘自随附的观测提案摘要：2011年诺贝尔物理学奖授予发现宇宙加速膨胀的科学家。暗能量调查（DES）的主要科学目标是解决这个问题：为什么宇宙的膨胀在加速？宇宙的加速是由于暗能量还是需要对广义相对论进行修改？如果是暗能量，它是真空的能量密度（爱因斯坦的宇宙常数）还是别的什么？DES将利用星系团、大规模星系团（包括重子声学振荡）、弱引力透镜和Ia型超新星四种互补技术，以前所未有的精度测量暗能量的特性，从而解决这些问题。为了达到所需的精度，我们将在525个晚上进行两次最佳交错调查：一个覆盖5000平方英尺的广域grizY调查；度至24等，并以5天的节奏进行更深的时域灰熊调查，覆盖30平方公里。为了响应2003年的NOAO AO， DES合作成立并建造了暗能量相机（DECam），这是一个5.7亿像素的红敏成像仪，具有2.2度的视场，五个均匀的高通量滤光片，一个五元光学校正器和一个六脚主动对焦和对准系统。我们已经构建并将运行一个数据管理系统来处理和服务DES调查数据，以及一个社区管道供NOAO处理社区数据。DES数据产品将为天文学界提供丰富的遗产，DECam作为布兰科望远镜的设施仪器将是一笔非凡的资产。

The following is taken from the abstract of the attached observing proposal: The Nobel Prize in Physics for 2011 was awarded for the discovery of the accelerating expansion of the Universe. The primary scientic objective of the Dark Energy Survey (DES) is to address the question: why is the expansion of the Universe speeding up? Is cosmic acceleration due to dark energy or does it require a modication of General Relativity? If dark energy, is it the energy density of the vacuum (Einstein's cosmological constant) or something else? DES will address these questions by measuring the properties of dark energy with unprecedented precision, using four complementary techniques: galaxy clusters, large-scale galaxy clustering (including baryon acoustic oscillations), weak gravitational lensing, and type Ia supernovae. To achieve the requisite precision, we will conduct two optimally interleaved surveys over 525 nights: a wide-area grizY survey covering 5000 sq. deg. to 24th mag and a deeper time-domain griz survey with 5-day cadence covering 30 sq. deg. In response to an NOAO AO in 2003, the DES collaboration was formed and has built the Dark Energy Camera (DECam), a 570-megapixel, red-sensitive imager with 2.2 degree field of view, five uniform, high-throughput filters, a five-element optical corrector, and a hexapod system for active focus and alignment. We have constructed and will operate a data management system to process and serve DES survey data and a Community Pipeline for NOAO to process community data. The DES data products will provide a rich legacy for the astronomy community, and DECam will be an extraordinary asset as a facility instrument on the Blanco Telescope.