Simultaneous observation of time variable TeV gamma-ray objects in optical wavelength and monitoring of night sky

活动星系核的伽马射线辐射在时间上变化很大，据报道其变化的时间尺度只有15分钟。其他波长的同步观测应该在与伽马射线观测相同的经度上进行。这项研究是不是我们在南澳大利亚伍梅拉袋鼠伽马射线望远镜旁边安装了一个小型光学望远镜来同时研究短时变率。此外，我们还计划监测伽马射线物体周围的夜空状况，以检查大气切伦科夫方法观测伽马射线的质量。今年，我们在千叶市鹿儿瓦校区运行了光学望远镜系统作为测试，并将其运往伍梅拉进行测试观测。我们使用Linux操作系统开发了一个全自动化的观测系统，使我们可以利用网络。它控制望远镜支架，并从冷却的CCD相机获取数据。在鹿儿瓦，我们成功地观测到了活动星系核，先生421。在伍梅拉，我们不得不每晚设置望远镜轴线，因为自动望远镜掩体不及时，每晚需要很长时间。然而，我们可以用约翰逊UBVRI滤光片在不同的天顶角测量恒星。通过与大气模型计算结果的比较，我们可以了解到Woomera的大气性质，这是切伦科夫观测中从观测光子数估算伽马射线能量的重要信息。

Gamma-ray emission from Active Galactic Nuclei is highly variable in time and the reported time scale of its variation is as short as 15 minutes. Simultaneous observation at other wavelength should be done at the same longitude as gamma-ray observation.Is this research we set a small optical telescope next to the KANGAROO gamma-ray telescope in Woomera, South Australia to study short time variability simultaneously. Also we aim to monitor night sky condition around the gamma-ray objects for quality check of gamma-ray observation by atmospheric Cherenkov method.This year we operated the optical telescope system in Kashiwa campus, Chiba, as a test and shipped it to Woomera for test observation. We developed a full automated observation system using Linux operating system so that we can utilize network. It controls the telescope mount and obtains data from the cooled CCD camera. At Kashiwa we succeeded in observing an AGN, Mrk421. At Woomera, we had to setup the telescope axis every night since the automated telescope shelter was not in time which required long time each night. However, we could measure stars at various zenith angles and with Johnson UBVRI filters. Comparing data with the model calculation of atmosphere, we could know the properties of atmosphere in Woomera, which is an important information when we estimate gamma-ray energy from observed number of photons in Cherenkov observation.