Universe Seen From Very High Energy Eyes

利用澳大利亚伍默拉的切伦科夫大气成像望远镜（2000年由7米望远镜扩建而成，由日本和澳大利亚机构联合运行），我们观测到了南半球超新星、超新星、活动星系核等活动天体的甚高能γ射线。第二、第三和第四台望远镜分别于2002年、2003年和2004年建成，我们开始对来自伽马射线簇射的切伦科夫光进行立体观测。虽然四台望远镜的阵列是在本项目的最后一年完成的，但我们已经积累了五年的观测数据，包括单台和立体观测数据。从数据中，我们发现了来自超新星RX J0854.0-4622、星暴星系NGC 253和银河系中心的高能γ射线信号，2）证实了我们先前对超新星RX J1713.7-3946和SN 1006以及脉冲星PSR 1704-44的探测，并扩展了观测光谱，3）我们探测到了来自活动星系核Mrk 421的最高能量γ射线; 4）我们确定了超新星SN 1987 A和脉冲双星PSR 1259-64/SS 2883的γ射线通量上限。我们的结果是揭示宇宙中粒子加速机制的关键观测，这直接关系到长期存在的宇宙线起源问题。

With an imaging atmospheric Cherenkov telescope of 10m diameter in Woomera, Australia, which was expanded from a 7m telescope in 2000 and was jointly operated by a consortium of Japanese and Australian institutions, we observed very high-energy gamma-rays from active celestial objects such as supernovae, pulsars, active galactic nuclei in the southern hemisphere. The second, third and fourth telescopes were build in 2002, 2003 and 2004, respectively, and we started stereoscopic observation of Cherenkov light from gamma-ray showers. With the stereoscopic method, angular resolution and energy resolution of gamma-ray events are improved and discrimination of gamma-ray events from background cosmic-ray showers became better than single telescope observations.Although the array of four telescopes was completed in the last year of the term of the project, we have accumulated observational data including single and stereoscopic observations for five years. From the data 1)we have discovered high-energy gamma-ray signals from a supernova RX J0854.0-4622, a starburst galaxy NGC253 and the Galactic center, 2)we have confirmed our previous detection of supernovae RX J1713.7-3946 and SN1006 and a pulsar PSR 1704-44 and extended the observed spectrum, 3)we have detected the most energetic gamma-rays from an active galactic nucleus Mrk421, and 4)we have set upper limits on gamma-ray fluxes from a supernova SN1987A and a pulsar binary PSR 1259-64/SS2883. Our results are the key observations to reveal particle acceleration mechanism in the Universe, which is directly related to the long-standing problem of the origin of cosmic rays.