Study of Ultra-High Energy Cosmic Rays at Tibetan highlands

青藏高原超高能宇宙线研究

• 批准号: 04044042
• 负责人: YUDA Toshinori
• 金额: $ 9.09万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04044042/
• 关键词: Tibet; Yangbajing; Air Shower Array; Interplanetary Magnetic Field; Solar Magnetic Field; Gamma-Ray; Cosmic Ray Origin; Crab Nebula; 太陽の影; 空気シャワー; 宇宙天体

The Tibet Air shower array at Yangbajing (4,300m, 90.5ﾟ E and 30.1ﾟ N) in Tibet has been operated continuously since January 1990, with Chinese scientists. The present array consists of 65 scintillation detectors which are placed in a lattice of 15m spacing. The mode energy of observed showers is estimated to be about 7 TeV for gamma rays. The angular resolution was well examined by observing the shadowing of cosmic rays by the moon. The moon shadow was observed with the significance of 7.1sigma and the angular resolution of the array is estimated to be 0.88ﾟ for showers with its mode energy 7 TeV and 0.52ﾟ for those with its mode energy 35 TeV.A small deflection of the shadow to the west by about 0.16ﾟ is comparable with that expected from the geomagnetic field effect.On the other hand, the sun shadow was observed in the direction away from the sun by 0.70ﾟ to the west and 0.40ﾟ to the south. This deflection is considered to be caused by the combined effect of the magnetic fields betw … More een the sun and the earth. Note that these data were taken when the sun was still in an active phase between 1990 and 1993. Such effect on the cosmic ray shadow is the first observation and is expected to bring us new information on the large scale structure of the solar and interplanetary magnetic field and its time variation.A search for steady emission of 10 TeV gamma rays has been made for various point sources including the Crab nebula, Cyg X-3 and Her X-1. For Cyg X-3, flux limits obtained at 10 TeV and 30 TeV for Cyg X-3 are far below the levels obtained by extrapolation of the Kiel flux. For the Crab nebula, the result obtained with no excess is inconsistent with the possitive results from the THEMISTOCLE experiment, while still being consistent with the Whipple new data. We also searched for gamma-ray emission from active galactic nuclei (AGNs) which have been reported to be poweful gamma-ray sources by EGRET on board the Compton GRO.In particular, the result for the nearest AGN,Markarian 421 at 10 TeV is interesting, and the further observation on this source will provide new information on the strength of infrared photon field in the universe. The present air shower array will be extended up to an effective area of 3.7 *10^4 m^2 in 1994. This array will consist of 221 scintilation detectors which are placed in a lattice of 15 m spacing. The trigger rate is taken to be about 250 Hz with a dead time less than 30 %. The mode energy for proton showers is estmated to be about 5 TeV.This new array will provide important information on the interplanetary magnetic field as well as acceleration of cosmic rays in the very near future. Less

自1990年1月以来，西藏的西藏空气淋浴阵列（4,300m，90.5 e e和30.1 n）在西藏一直连续运行。目前的阵列由65个闪烁检测器组成，这些镜头探测器放置在15m间距的晶格中。据估计，观察到的淋浴的模式对于伽马射线的模式约为7 TEV。通过观察月球对宇宙射线的阴影，可以很好地研究角度分辨率。观察到月亮的阴影，其显着性为7.1凹形，阵列的角度分辨率估计为0.88 ﾟ，对于具有其模式7 TEV的阵阵阵阵阵阵阵列7 TEV和0.52℃，对于那些具有其模式35 TEV的人35 Tev.a tev.16 te的偏向于0.16 ﾟ的偏向于0.16 ﾟ的预期与GEOMAGNETIC TASDIT相提并论。 0.70 ﾟ向西，南部为0.40 ﾟ。该定义被认为是由磁场的综合作用引起的……太阳和地球更加含量。请注意，当太阳在1990年至1993年之间仍处于活跃的阶段时，采取了这些数据。这种对宇宙射线阴影的影响是第一个观察结果，预计将为我们带来有关太阳能和星际磁场的大规模结构及其时间变化的新信息。搜索了10个TEV Gamma射线的稳定排放，以使包括Crab Nebula在内的各种点源排放到包括Crab Nebula，Cyg，Cyg，Cyg x-1。对于CYG X-3，在10 TEV和30 TEV处获得的通量极限远低于通过外推Kiel通量获得的水平。对于螃蟹星云，没有过量的结果与Themistocle实验的积极结果不一致，同时仍然与Whipple新数据保持一致。 We also searched for gamma-ray emission from active galactic nuclear (AGNs) which have been reported to be poweful gamma-ray sources by EGRET on board the Compton GRO.In particular, the result for the nearest AGN,Markarian 421 at 10 TeV is interesting, and the further observation on this source will provide new information on the strength of infrared photon field in the universe.目前的空气淋浴阵列将在1994年延伸至3.7 *10^4 m^2的有效面积。该阵列将由221个闪烁检测器组成，该检测器放置在15 m间距的晶格中。触发率约为250 Hz，耗时小于30％。估计质子淋浴的模式能量约为5 tev。此新阵列将在不久的将来提供有关星际磁场以及宇宙射线加速的重要信息。较少的

项目成果

T.Saito, T.Yuda, K.Kasahara et al.: "Intenisty of protons at the "knee" energy of primary cosmic rays." Astrophysical Journal. 2. 257-267 (1993)

T.Saito、T.Yuda、K.Kasahara 等人：“初级宇宙射线“膝”能量处的质子强度。”

M.Amenomori et al.: "Cosmic ray deficits from the directions of the Moon and the Sun detected with the Tibet air shower array" Physical Review D. 47. 2675-2681 (1993)

M.Amenomori 等人：“西藏空气簇射阵列检测到的来自月球和太阳方向的宇宙射线缺陷”《物理评论》D. 47. 2675-2681 (1993)

M.Amenomori,Z.Cao,T.Yuda et al.20GB05:Search for steady emission of 10-TeV gamma-rays from the Crab Nebula,Cygnus X-3 and Hercules X-1 using the Tibet-air shower array: Physical Review Letters. 69. 2648-2471 (1992)

M.Amenomori,Z.Cao,T.Yuda 等人20GB05：利用西藏空气簇射阵寻找蟹状星云、天鹅座 X-3 和武仙座 X-1 的 10-TeV 伽马射线稳定发射：物理

M.Amenomori et al.: "Direct evidence of the interplanetray magnetic field effect on the cosmic ray shadow by the sun" The Astrophysical Journal. 415. L147-L150 (1993)

M.Amenomori 等人：“行星际磁场对太阳宇宙射线阴影影响的直接证据”《天体物理学杂志》。

M. AMENOMORI et al.: "Recent results of the Tibet AS-G experiment" AIP Conference Proceedings. (1992)

M. AMENOMORI 等人：“西藏 AS-G 实验的最新结果”AIP 会议记录。