Detector Characterization to Enable Discovery of Gravitational Waves with Advanced LIGO

爱因斯坦发现的广义相对论告诉我们，人们熟悉的日常引力是某种更奇怪的东西的表现：物质扭曲了时空的几何形状。在该理论的关键预测中，包括膨胀的宇宙和黑洞的存在，是引力波(GW)的存在：大质量的快速运动导致时空几何中以光速运动的涟漪。虽然在对致密恒星的双星系统的间接影响方面得到了很好的测试，但直接探测入射到地球上的引力波构成了一个突出的挑战。实现这一能力的科学回报将是巨大的--从探索恒星爆炸的极端动力学到收集几乎在大爆炸时刻的宇宙状态信息。这一新的宇宙窗口的努力占据了几十年的实验和技术发展，推动了物理科学中不同领域的边界。2015年将是引力波物理学备受期待的分水岭时刻：两个先进的激光干涉仪引力波天文台(ALIGO)探测器将开始进行初始数据采集，随后欧洲先进的处女座引力波观测站将投入使用。ALIGO探测器的灵敏度将提高到比第一代探测器高约十倍，为观测GW源开辟了一个比以前大1000倍的空间体积。锡拉丘兹小组将支持LIGO科学合作组织从由中子星和/或黑洞组成的双星系统(称为致密双星聚合，简称CBC)中搜索引力波信号。它的特别重点将是研究仪器伪迹(称为“毛刺”)模仿真实信号的方式，并开发新的工具来区分毛刺和真实信号。因为来自双星的引力波形可以很好地预测，所以已经开发了一些特殊的技术来帮助区分。然而，这些方法不足以满足高级LIGO所期望看到的全部二进制文件。锡拉丘兹小组将开发新的工具来处理这些更脆弱的信号。锡拉丘兹小组将通过三种基本方法在其第一次观测运行(称为“O1”)中支持使用高级LIGO(“aLIGO”)搜索CBC信号。首先，他们将调优、运行并应用名为“Daily CBC”的特殊诊断工具，该工具可以在任何LIGO数据偏离高斯的情况下向专员提供快速反馈。其次，他们将开发一种新的专门针对LIGO标准工具的版本，用于调查毛刺和候选信号之间的统计相关性；由于CBC信号的持续时间较长，在询问毛刺是否与CBC信号在时间上一致之前，有必要实施调谐的时移方法。最后，他们将使用相关技术实施一种新的统计测试，以衡量产生候选信号的数据看起来更像是真实信号还是故障。这些技术将使在O1(以及更远的地方)对CBC信号的搜索发挥其潜力，使aLIGO更有可能成功地从这些迷人的物体上探测到信号。

The General Theory of Relativity discovered by Einstein tells us that the familiar, everyday force of gravity is a manifestation of something much stranger: the bending of the geometry of space-time by matter. Among the key predictions of the theory, which includes the expanding Universe and the existence of black holes, is the existence of gravitational waves (GW): ripples moving at the speed of light in the geometry of space-time caused by the fast motion of large masses. Although well tested in terms of their indirect effects on binary systems of compact stars, the direct detection of gravitational waves incident on Earth poses an outstanding challenge. The scientific rewards from achieving this ability would be enormous - ranging from probing the extreme dynamics of exploding stars to gleaning information about the state of the Universe almost at the moment of the Big Bang itself. The effort to enable this new window on the universe has occupied several decades of experimental and technological developments that have pushed the boundaries across diverse fields in the physical sciences. The year 2015 will mark a highly-anticipated watershed moment for gravitational-wave physics: The two advanced Laser Interferomenter Gravitational Wave Observatory (aLIGO) detectors will start their initial data taking runs, followed by the commissioning of the advanced Virgo gravitational wave observatory in Europe. The sensitivity of the aLIGO detector will be ramped up to become about ten times better than that of the first-generation detectors, opening up a spatial volume for observing GW sources that will be 1000 times larger than before. The Syracuse group will support the LIGO Scientific Collaboration's search for gravitational wave signals from binary star systems consisting of neutron stars and/or black holes (called compact binary coalescences, or "CBC's"). Its special focus will be to study the ways in which instrumental artifacts (called "glitches") can mimic genuine signals, and to develop new tools to distinguish glitches from genuine signals. Because the gravitational waveforms from binaries can be very well predicted, some special techniques have already been developed that help make the distinction. However, these methods do not suffice for the full range of binaries expected to be seen with Advanced LIGO. The Syracuse group will develop new tools that will work on these more vulnerable kinds of signals. The Syracuse group will support the search with Advanced LIGO ("aLIGO") for CBC signals in its first observing run (called "O1") with three basic approaches. Firstly, they will tune, run, and apply the special diagnostic tool called "Daily CBC", which gives rapid feedback to commissioners on any departures of aLIGO data from Gaussianity. Secondly, they will develop a new specially-focused version of LIGO's standard tool for investigating the statistical correlation between glitches and candidate signals, hveto; because of the long duration of CBC signals, it is necessary to implement a tuned time-shift method before asking if a glitch is coincident in time with a CBC signal. Finally, they will use related technology to implement a new statistical test that measures whether the data yielding a candidate signal looks more like a true signal or like a glitch. These techniques will enable searches for CBC signals in O1 (and beyond) to live up to their potential, making it substantially more likely that aLIGO will be succeed in detecting signals from these fascinating objects.