用地面阵列寻找TeV能区γ点源的方法探讨

文中探讨搜寻TeV能区γ点源的方法.讨论利用student变量t判断来自源区及背景区宇宙线事例的统计差别,并由Bayes定理与MonteCarlo模拟相结合计算源区各能段的信号数,推算蟹状星云在TeV能区的γ射线微分能谱     

利用羊八井广延大气簇射阵列探测来自壳型超新星遗迹G40.5-0.5的TeV Gamma射线发射

利用羊八井广延大气簇射阵列从2000年10月到2001年9月的数据,对壳型超新星 遗迹G40.5-0.5可能的TeV gamma射线发射进行了探测. 用对扩展源的二维分析方法发现一个最高超出为4.4σ的天区,EGRET不明源GeV J1907+0557非常接近 这一最高超出天区的中心.     

An updated search of steady TeV γ-ray point sources in northern hemisphere using the Tibet air shower array

Using the data taken from Tibet II High Density (HD) Array (1997 February—1999 September) and Tibet-III array (1999 November—2005 November), our previous northern sky survey for TeV γ-ray point sources has now been updated by a factor of 2.8 improved statistics. From 0.0° to 60.0° in declination (Dec) range, no new TeV γ-ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV γ-ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits.     

羊八井ARGO实验对Crab源灵敏度的研究

应用Monte-Carlo研究给出羊八井ARGO(AstrophysicalRadiationwithGround-basedObservatory)实验的角分辨能力.采用Whipple实验给出的蟹状星云(CrabNebula)TeV能区的微分流强参量,对3种统计显著性的方法进行了比较,研究表明:以信号和本底的似然比为权重的加权方法能够给出最优化的结果.在没有考虑γ/p鉴别能力的条件下,ARGO实验运行一年能够观测到来自Crab源累计超出平均可达18σ显著水平,以5σ为标准,实验可达到小于0.3I_crab的灵敏度.