MULTI-TeV GAMMA-RAY OBSERVATION FROM THE CRAB NEBULA USING THE TIBET-III AIR SHOWER ARRAY FINELY TUNED BY THE COSMIC RAY MOON'S SHADOW
MULTI-TeV GAMMA-RAY OBSERVATION FROM THE CRAB NEBULA USING THE TIBET-III AIR SHOWER ARRAY FINELY TUNED BY THE COSMIC RAY MOON'S SHADOW
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DOI：
10.1088/0004-637x/692/1/61
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发表时间：
2008-10
期刊：
影响因子：
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通讯作者：
M. Amenomori;X. Bi;D. Chen;S. Cui;Danzengluobu;L. Ding;X. Ding;C. Fan;C. Feng;Zhaoyang Feng;Z. Feng;Xiang Gao;Q. Geng;H. Guo;H. He;M. He;K. Hibino;N. Hotta;Haibing Hu;H. Hu;J. Huang;Q. Huang;H. Jia;F. Kajino;K. Kasahara;Y. Katayose;C. Kato;K. Kawata;Labaciren;G. Le;A. Li;J. Li;Y. Lou;H. Lu;S. L. Lu;X. Meng;K. Mizutani;J. Mu;K. Munakata;A. Nagai;H. Nanjo;M. Nishizawa;M. Ohnishi;I. Ohta;H. Onuma;T. Ouchi;S. Ozawa;Jie Ren;T. Saito;T. Saito;M. Sakata;T. Sako;M. Shibata;A. Shiomi;T. Shirai;H. Sugimoto;M. Takita;Y. Tan;N. Tateyama;S. Torii;H. Tsuchiya;S. Udo;B. Wang;Hong Wang;X. Wang;Y. Wang;Y. Wang;H. Wu;L. Xue;Y. Yamamoto;C. Yan;X. Yang;S. Yasue;Z. Ye;G. Yu;A. Yuan;T. Yuda;H. Zhang;J. Zhang;N. Zhang;X. Zhang;Y. Zhang;Yi. Zhang;Zhaxisangzhu;X. Zhou
中科院分区：
文献类型：
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作者：
M. Amenomori;X. Bi;D. Chen;S. Cui;Danzengluobu;L. Ding;X. Ding;C. Fan;C. Feng;Zhaoyang Feng;Z. Feng;Xiang Gao;Q. Geng;H. Guo;H. He;M. He;K. Hibino;N. Hotta;Haibing Hu;H. Hu;J. Huang;Q. Huang;H. Jia;F. Kajino;K. Kasahara;Y. Katayose;C. Kato;K. Kawata;Labaciren;G. Le;A. Li;J. Li;Y. Lou;H. Lu;S. L. Lu;X. Meng;K. Mizutani;J. Mu;K. Munakata;A. Nagai;H. Nanjo;M. Nishizawa;M. Ohnishi;I. Ohta;H. Onuma;T. Ouchi;S. Ozawa;Jie Ren;T. Saito;T. Saito;M. Sakata;T. Sako;M. Shibata;A. Shiomi;T. Shirai;H. Sugimoto;M. Takita;Y. Tan;N. Tateyama;S. Torii;H. Tsuchiya;S. Udo;B. Wang;Hong Wang;X. Wang;Y. Wang;Y. Wang;H. Wu;L. Xue;Y. Yamamoto;C. Yan;X. Yang;S. Yasue;Z. Ye;G. Yu;A. Yuan;T. Yuda;H. Zhang;J. Zhang;N. Zhang;X. Zhang;Y. Zhang;Yi. Zhang;Zhaxisangzhu;X. Zhou
由533个闪烁探测器组成的Tibet-III空气簇射阵列自1999年以来一直在中国西藏羊八井成功运行。利用该阵列从1999年11月到2005年11月收集的数据集，我们获得了蟹状星云γ射线的能谱，其能量范围为1.7-40 TeV，可用幂律表示为（dJ/dE）=（2.09 ± 0.32）× 10−12（E/3 TeV）−2.96±0.14 cm−2 s−1 TeV−1。这一结果与其他通过切伦科夫望远镜成像的独立γ射线观测结果一致。在本文中，我们仔细检查和调整西藏-III阵列的性能，使用月球阴影的数据与详细的蒙特卡罗（MC）模拟进行比较。由于地磁场的影响，阴影会移到月球视位置的西边，尽管这种位移的程度取决于带正电的宇宙射线的初级能量。这一发现使我们能够估计系统误差，在确定初级能源从它的簇射大小。在我们的实验中，这个误差估计小于±12%。这种能量尺度估计是在地面宇宙线实验中的第一次尝试。系统指向误差小于0.°011。亏损率和月球阴影的位置是非常稳定的，每年的统计误差为±6%。这保证了西藏-III台阵点状源观测的长期稳定性。这些系统误差在我们对蟹状星云的研究中得到了充分的考虑。
The Tibet-III air shower array, consisting of 533 scintillation detectors, has been operating successfully at Yangbajing in Tibet, China since 1999. Using the data set collected by this array from 1999 November through 2005 November, we obtained the energy spectrum of γ-rays from the Crab Nebula, expressed by a power law as (dJ/dE) = (2.09 ± 0.32) × 10−12(E/3 TeV)−2.96±0.14 cm−2 s−1 TeV−1 in the energy range of 1.7–40 TeV. This result is consistent with other independent γ-ray observations by imaging air Cherenkov telescopes. In this paper, we carefully checked and tuned the performance of the Tibet-III array using data on the Moon's shadow in comparison with a detailed Monte Carlo (MC) simulation. The shadow is shifted to the west of the Moon's apparent position as an effect of the geomagnetic field, although the extent of this displacement depends on the primary energy of positively charged cosmic rays. This finding enables us to estimate the systematic error in determining the primary energy from its shower size. This error is estimated to be less than ±12% in our experiment. This energy scale estimation is the first attempt among cosmic ray experiments at ground level. The systematic pointing error is also estimated to be smaller than 0.°011. The deficit rate and the position of the Moon's shadow are shown to be very stable within a statistical error of ±6% year by year. This guarantees the long-term stability of pointlike source observation with the Tibet-III array. These systematic errors are adequately taken into account in our study of the Crab Nebula.