Astroparticle Physics with MILAGRO

MILAGRO 的天体粒子物理学

• 批准号: 0245234
• 负责人: Gaurang Yodh
• 金额: $ 70.5万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0245234&HistoricalAwards=false
• 关键词: Astroparticle; Physics; MILAGRO

This is a proposal to operate the full Milagro air shower telescope,the Milagro pond andthe surrounding array of outrigger water tanks,for the next three years and analyze thedata to study the generation of TeV gamma rays from extremely energetic cosmic objects,such as nearby Active Galactic Nuclei (Blazars),Gamma Ray Bursts(GRB)and steadyemitters in our own Galaxy.Study of TeV gamma rays from sources provides a sensitivetool for understanding the mechanisms for particle acceleration and subsequent gamma raygeneration.TeV gamma rays from GRBs of short duration may allow s to test for possibleenergy dependence of the speed of light as predicted by theories of quantum gravity.Theupper end of the gamma ray spectrum is particularly sensitive to the bulk Lorentz factorand magnetic .elds of the source shock.The shape at TeV energies can provide a probe ofthe extra-galactic IR absorption.Milagro is a water Cherenkov air shower telescope.It consists of a 5000 m 2 central pondand an array of 175 water tanks distributed out to 120 meters from the center of the pond.Its point spread function for gamma rays has a width of 0.8 deg.Its strengths are:all-skysensitivity,continuous 24 hour operation and ability to study transients on many di .erenttime scales.Milagro will be the only contin ously operating TeV gamma ray telescopebefore GLAST will operate.Milagro is a collaboration of Irvine(UCI),Santa Cruz(UCSC)and Riverside(UCR),LANL,Maryland,New Hampshire,NYU and GMU groups.In the last three year grant,we have operated full Milagro pond detector at a data rate of1700 Hz.We have developed a new trigger to be able to study GRBs down to a few hundredGeV so that we can be sensitive to GRBs out to a red shift of 0.4.We have completed thearray of 175 outrigger tanks to be able to locate shower cores out to about 100 meters whichwill improve our pointing and angular resolution substantially.We have working algorithmsto reject more than 90 percent of cosmic ray triggers while keeping more than 50 percent ofgamma ray triggers.We have implemented on-line capability of detecting bursts or transientsin real-time,within 5 minutes and sending out alerts for m ltifrequency searches.We haveobserved the steady Crab at greater than 5 sigma.We have observed Mrk421 during itsactive phase in 2001.We have observed a 30 sigma de .cit for the shadow of the moon in ayear of operation which provides direct energy calibration of Milagro and enables search ofanti-proton component of cosmic rays in the TeV energy range.We have begun the studyof gamma rays expected from cosmic ray interactions in the galaxy in TeV energy range.Milagro not only makes a signi .cant contribution to high energy astrophysics but alsoprovides an excellent tool for teaching,training and learning for graduate students,under-graduate students and science teachers from K-12.With its location in New Mexico,itprovides research and learning experience to Native Americans.At UCI,we have developededucational outreach activities for research experience to undergraduates as a part of on-going UCI REU program,to train high school science teachers through the COSMOS andQuarknet programs of UCI.The UCI Milagro group will continue to provide training toundergraduate and graduate students to work on di .erent aspects of the research and onsite work at the Milagro site for gaining real research experience.

这是一项在未来三年内运行完整的米拉格罗空气淋浴望远镜、米拉格罗池塘和周围的悬臂水箱阵列的提议，并分析数据，以研究来自极高能量宇宙物体的TeV伽马射线的产生，例如附近的活动星系核（Blazars），伽玛射线暴对TeV源γ射线的研究为理解粒子辐射机制提供了灵敏的工具短持续时间伽玛暴产生的TeV γ射线可以用来检验量子引力理论所预言的光速与能量的关系。γ射线谱的上端对体洛伦兹因子和源激波的磁场特别敏感。TeV能量下的形状可以提供一个探测超光速的探针。银河系红外吸收。Milagro是一个水切伦科夫空气簇射望远镜。它由一个5000平方米的中心水池和一个由175个水箱组成的阵列组成，这些水箱分布在距水池中心120米的地方。它的伽马射线点扩散函数的宽度为0.8度。它的优点是：全天空灵敏度，连续24小时运行，并能够在许多不同的时间尺度上研究瞬态。Milagro将是GLAST运行之前唯一连续运行的TeV伽马射线望远镜。Milagro是欧文（UCI），圣克鲁斯（UCSC）和滨江（UCR），LANL，马里兰州，新罕布什尔州，在过去三年的资助中，我们已经以1700 Hz的数据速率运行了完整的米拉格罗池塘探测器。我们已经开发了一种新的触发器，能够研究几百GeV的伽马射线暴，这样我们就可以对红移为0.4的伽马射线暴敏感。我们已经完成了175个悬臂箱的阵列，能够定位大约100米，这将大大提高我们的指向和角分辨率。我们有工作算法拒绝超过90%的宇宙射线触发，同时保持超过50%的伽马射线触发。我们已经实现了实时检测爆发或瞬变的在线能力，在5分钟之内，并发出警报，为多频搜索。我们已经观察到稳定的螃蟹在大于5西格玛。我们已经观察到Mrk 421在其活动期间我们在一年的运行中观测到了30 sigma de .cit的月球阴影，这为Milagro提供了直接的能量校准，并使反我们已经开始研究TeV能量范围内宇宙射线相互作用产生的伽马射线。Milagro不仅对高能天体物理学做出了重大贡献，也提供了一个很好的工具，教学，培训和学习的研究生，本科生和科学教师从K-12.With它的位置在新墨西哥州，它提供了研究和学习经验，以美洲原住民。在UCI，我们已经开发了教育推广活动的研究经验，以本科生作为一个正在进行的UCI REU计划的一部分，通过UCI的COSMOS和Quarknet计划培训高中科学教师。UCI Milagro集团将继续为研究生和研究生提供培训，以从事研究的各个方面和Milagro现场工作，真实的研究经验。