Investigation of dark matter with microlensing search

我们在新西兰约翰山大学天文台用61厘米反射望远镜和MOAcam 2大型CCD相机对大麦哲伦云和银河系隆起进行了微透镜观测。已经进行了实时分析，以发布发现的微透镜事件的警报。在此期间发出的警报数量为：2001年54次，2002年63次，2003年74次。在后续观测中，发现了太阳系外行星OGLE-2003-235/MOA-2003-53的强候选者。Sumi对银河系隆起的微透镜事件进行了广泛的研究。结果表明，鼓包为棒状结构。对包括视差效应的凸出事件的分析已经发现了6个视差候选。这种技术对LMC事件特别有用，因为可以确定到透镜物体的距离。对LMC数据的分析仍在进行中，目前的候选星有4颗。微透镜搜索的数据库也被用来研究变星。对长周期变星的分析已经做了广泛的研究。结果表明，Miras的周期-震级关系清晰。这一结果表明，Miras可以用于距离测量。太阳系外行星的探测器已经完成，已经发现了52颗候选行星。2002财政年度，批准了新望远镜的补助金提案。新的1.8米望远镜将安装在约翰山大学天文台。用新望远镜进行微透镜搜索和用61厘米望远镜进行后续观测将接管微透镜科学。

We have executed microlensing survey toward Large Magellanic Cloud (LMC) and Galactic bulge using 61 cm reflector telescope and large COD camera MOAcam2 at Mt.John University Observatory, New Zealand. Real-time analyses have been made to issue alerts of discovered microlensing events. The numbers of alerts issued in this period is 54 in 2001, 63 in 2002, and 74 in 2003. From the follow-up observations, strong candidate of the extrasolar planet OGLE-2003-235/MOA-2003-53 was discovered. Extensive studies of the microlensing events toward Galactic bulge has been made by Sumi. The result indicates that the bulge has bar structure. The analysis of the bulge events including parallax effect have found 6 parallax candidates. This technique is particularly useful to LMC events, because the distance to the lensing object can be determined. The analysis of LMC data is still underway, and present number of candidates is 4.The data base for the microlensing search is used to investigate variable stars too. Analysis of long-period variable stars has been made extensively. The result show clear period-magnitude relation of Miras. This result indicates that Miras can be used for measurements of distance. Searches for extrasolar planets have been made and 52 candidates have been found.In FY2002, the Grant-in-Aid proposal for new telescope was approved. The new 1.8 m telescope will be installed in Mt.John University Observatory. Microlensing search with new telescope and follow-up observations with 61 cm telescope will take over microlensing science.