Analysis of IceCube Data

IceCube数据分析

• 批准号: 0554699
• 负责人: P. Buford Price
• 金额: $ 45万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0554699&HistoricalAwards=false
• 关键词: Analysis; IceCube; Data

nalysis of IceCube Data During the Three Year Period Beginning May 2006P. B. Price, Physics Dept., U. C. Berkeley The Berkeley group led by P. B. Price has participated in the AMANDA high-energy neutrino astrophysics project since its inception in 1991. Beyond their participation in the construction of the growing IceCube observatory, this new grant will provide some support to the present group of 12 researchers as they analyze data flowing from IceCube. Here are a few of the topics they will study: - Development of algorithms for analysis of electromagnetic cascades induced by electron neutrinos. They will be used to study high-energy cascades of both atmospheric and astrophysical origin. - Using their new reconstruction algorithms, they will look for neutrinos produced by giant flares from powerful extragalactic sources of high energy neutrinos. - They will exploit their method for increasing signal to noise by "stacking" data from particular families of point sources of high energy neutrinos with the expectation of seeing neutrinos from certain classes of active galaxies. - By means of a special "slow-particle trigger", they will search for hypothetical particles such as strangelets, supermassive magnetic monopoles, and Q-balls that will pass through much of the earth without significant slowing and that can be recognized by their slow speed (less than 1% the speed of light). - Theorists have recently calculated that neutrinos with energy up to a trillion electron volts generated in core-collapse extragalactic supernovae may be detectable in IceCube for sources at distances within about 50 million light years of Earth. An unmistakable signal would be the detection of at least two such neutrinos from the same direction in the sky within a few seconds. Such a discovery would have great significance for astrophysics, gravitational physics, and relativity.The Berkeley group has led in inventing new devices for AMANDA and IceCube and in applying them to totally different topics at the forefront of science. The first such device was their laser-powered dust logger, which they have used to detect volcanic ash layers and climate-correlated dust concentrations, by means of which they discovered a causal relationship between large volcanic eruptions and abrupt climate change. By adding fluorescence channels to the dust logger, they created a biologger, with which they can detect various classes of microbes that contain molecules such as chlorophyll and tryptophan (an amino acid in all cells) whose fluorescence induced by the biologger allows them to study the history of microbial deposition and its possible correlation with climate and volcanism. A very recent example of the breadth of their interest is their realization that the explanation of the mysterious increase in phototube noise near the bottom of the IceCube strings is the light emitted by the glacial ice at great depths where the temperature is warm enough to allow shear of the flowing ice to develop, during which visible light and sound are produced. This poorly understood optical phenomenon of triboluminescence induced during jerky deformation of certain solids such as ice will be studied using IceCube data. There will no doubt be new spinoffs as they analyze ongoing IceCube data.

从2006年5月开始的三年期间的IceCube数据分析。加州大学伯克利分校物理系B·普莱斯由P·B·普莱斯领导的伯克利小组自1991年阿曼达高能中微子天体物理项目成立以来一直参与该项目。除了参与不断扩大的冰立方天文台的建设外，这笔新的赠款还将为目前的12名研究人员分析来自冰立方的数据提供一些支持。以下是他们将研究的几个主题：-分析电子中微子诱导的电磁级联的算法的发展。它们将被用来研究大气和天体物理来源的高能级联。-使用他们的新重建算法，他们将从强大的河外高能中微子源中寻找由巨型耀斑产生的中微子。-他们将利用他们的方法来增加信噪比，方法是将来自特定高能中微子点源家族的数据堆叠在一起，期望看到来自某些类型活动星系的中微子。--通过一种特殊的“慢粒子触发器”，他们将搜索假设的粒子，如奇异星、超大质量磁单极子和Q球，这些粒子将通过地球的大部分地区而不会显著减速，并且可以通过它们的缓慢速度(低于光速的1%)来识别。-理论家最近计算出，在核心塌缩的河外超新星中产生的能量高达1万亿电子伏特的中微子，可能会在距离地球约5000万光年的源的冰立方中被探测到。一个明确的信号将是在几秒钟内从天空中同一方向探测到至少两个这样的中微子。这样的发现将对天体物理学、引力物理学和相对论具有重大意义。伯克利大学领导的团队为阿曼达和冰立方发明了新的设备，并将它们应用于科学前沿的完全不同的主题。第一个这样的设备是他们的激光驱动的粉尘记录器，他们用它来探测火山灰层和与气候相关的粉尘浓度，通过它他们发现了大规模火山喷发和气候突然变化之间的因果关系。通过在尘埃记录仪上添加荧光通道，他们创造了一个生物记录仪，用它他们可以检测到含有叶绿素和色氨酸(所有细胞中的一种氨基酸)等分子的各种微生物，通过生物记录仪诱导的荧光，他们可以研究微生物沉积的历史及其与气候和火山活动的可能关联。他们感兴趣的一个最近的例子是他们意识到冰立方弦底部附近光管噪音神秘增加的解释是冰川冰在很深的地方发出的光，那里的温度足够温暖，允许流动的冰发生剪切，在此期间产生可见光和声音。这一鲜为人知的摩擦发光光学现象是在某些固体(如冰)的急变变形过程中引起的，我们将使用冰立方数据对其进行研究。毫无疑问，在他们分析正在进行的冰立方数据时，将会有新的衍生产品。