Analysis of IceCube Data

分析冰立方数据在三年期间开始2006年5月P。B。普赖斯，物理系，联合C.伯克利伯克利小组由P. B领导。自1991年AMANDA高能中微子天体物理项目成立以来，普莱斯一直参与该项目。除了参与建设不断发展的IceCube天文台之外，这笔新的赠款还将为目前的12名研究人员提供一些支持，因为他们分析了来自IceCube的数据。以下是他们将研究的一些主题： - 电子中微子诱发电磁级联分析算法的发展。它们将被用来研究大气层和天体物理起源的高能级联。 - 利用他们新的重建算法，他们将寻找来自强大的河外高能中微子源的巨大耀斑产生的中微子。 - 他们将利用他们的方法，通过“堆叠”来自特定高能中微子点源家族的数据来增加信噪比，以期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”，他们将寻找假设的粒子，如奇异粒子，超大质量磁单极子和Q球，这些粒子将穿过地球的大部分区域而不会显着减慢，并且可以通过它们的慢速度（小于光速的1%）来识别。 - 理论家最近计算出，在核心坍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，可能在距离地球约5000万光年的冰立方中被探测到。一个明确无误的信号将是在几秒钟内从天空的同一方向探测到至少两个这样的中微子。这样的发现对天体物理学、引力物理学和相对论都有重大意义。伯克利小组已经率先为AMANDA和IceCube发明了新设备，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灰尘记录仪，他们用它来检测火山灰层和与气候相关的灰尘浓度，通过这种方法，他们发现了大规模火山爆发和突然的气候变化之间的因果关系。通过将荧光通道添加到灰尘记录仪，他们创建了一个生物记录仪，他们可以检测含有叶绿素和色氨酸（所有细胞中的氨基酸）等分子的各种微生物，生物记录仪诱导的荧光使他们能够研究微生物沉积的历史及其与气候和火山活动的可能相关性。最近的一个例子表明了他们的兴趣范围之广，他们意识到，冰立方弦底部附近光电管噪音神秘增加的解释是，在很深的地方，冰川冰发出的光足够温暖，允许流动冰的剪切发展，在此期间产生可见光和声音。这种知之甚少的光学现象，摩擦发光过程中引起的急动变形的某些固体，如冰将使用IceCube数据进行研究。毫无疑问，当他们分析正在进行的IceCube数据时，会有新的副产品。

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.