月亮阴影与羊八井二期阵列的角分辨

The Moon's Shadow and the Tibet Ⅱ Array's Angular Resolution

利用１９９５年１０月至１９９７年９月间采集到的数据，西藏空气簇射二期阵列以１４．３σ，１３．６σ的显著性观测到了７ＴｅＶ及３０ＴｅＶ宇宙线的月亮阴影；利用最大似然法定出阵列相应的角分辨分别为０．８８＋０．０５°－０．０３°，０．４２＋０．０４°－０．００°，地磁场分别使月亮阴影偏向南０．０４°±０．０８°，０．０４°±０．０６°，由此可推知该阵列对簇射方向定向的系统误差小于０．１°．

Using the data obtained in the period of October 1995—September 1997,the shadow of the Moon has been detected at 14.3σ and 13.6σ level respectively with its mode energies 7 and 30TeV.Using the maxumum likelihood method,the angular resolutions estimated are 0.88 ° +0.05° -0.03° and 0 42 ° +0.04° -0.00° .The effect of geomagnetic makes the shadows shift 0 04°±0.08° and 0.04°±0.06° to the south respectively.Based on this,the overall pointing error of the array is estimated to be smaller than 0.1°.