标题： 银河微透镜效应的差异图像分析 II。 微透镜事件 显示英文标题

标题： Difference Image Analysis of Galactic Microlensing II. Microlensing Events

摘要： MACHO合作项目自1996年以来一直在进行差分图像分析（DIA），目的是提高对引力微透镜检测的灵敏度。 这是关于将DIA应用于一个天区银河系核球图像的应用报告。 我们展示了DIA技术如何通过消除传统测光方案的位置依赖性并降低微透镜事件检测阈值，显著增加检测到的透镜事件数量。 与PSF测光不同，该技术能给出未混合的微透镜源星的颜色和位置。 我们提出了一套从使用该技术发现的天体中选择微透镜事件的标准。 介绍了使用DIA技术发现的16像素和经典微透镜事件。 显示英文摘要

摘要： The MACHO collaboration has been carrying out Difference Image Analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to galactic bulge images in one field. We show how the DIA technique significantly increases the number of detected lensing events, by removing the positional dependence of traditional photometry schemes and lowering the microlensing event detection threshold. This technique, unlike PSF photometry, gives the unblended colours and positions of the microlensing source stars. We present a set of criteria for selecting microlensing events from objects discovered with this technique. The 16 pixel and classical microlensing events discovered with the DIA technique are presented.