麦哲伦巡天数据分析

发布时间：2018-07-22 16:49

【摘要】：麦哲伦星云是离我们银河系最近的星系，也是我们银河系的卫星星系。麦哲伦星云的低金属丰度环境和离我们较近的距离非常有利于恒星、星团、行星状星云和星系相互作用等科研目标的研究，这些因素使得它成为我们感兴趣的目标天体系统。 VISTA survey of Magellanic Clouds system (VMC)巡天是欧洲南方天文台针对麦哲伦星云的巡天项目，它提供了近红外Y、J、Ks三个波段的观测图像。观测图像覆盖了大小麦哲伦星云的主要区域、它们相互连接的部分以及部分星流区域。这是目前对麦哲伦星云的巡天范围最广、测光深度较深的观测图像。作为VMC巡天项目的重要组成部分，巡天数据由VISTA巡天数据处理系统（pipeline)提供，它对原始观测图像进行处理，包括点源的目标提取、测光，并提供最终源表。由于巡天数据处理系统（pipeline)基于通常科研目标设计，并不针对较暗的源。很多研究要求较精确的暗端数据，数据在一定完备度上有更低的下限,而巡天数据处理系统的处理结果并无法满足这一要求。针对这个问题，我们选择了VMC已完成的巡天区域，通过对原始数据处理，合并多个时期的巡天数据，手动进行PSF测光，获得了我们最新的源表，进而进行分析，对整个数据在暗端的表现进行了详细描述，，最终提供了一套针对暗端天体目标研究所需的数据处理方法。我们的结果描述包括： 1.研究区域的点扩散函数无系统性变化。 2.孔径测光与点扩散函数测光在处理VMC巡天数据时的表现以及它们对暗源的区别。 3.新源表跟pipeline的区别主要体现在测光精度更高，在暗端有效源的数目高出至少30%(取决于波段、观测区域） 4.随位置变化的完备性曲线。 5.不同恒星密度区域的光度函数。
[Abstract]:The Magellanic Nebula is the nearest galaxy to our Milky way and the satellite galaxy of our Milky way. The low metal abundance environment of the Magellanic Nebula and its proximity to us are very useful for the study of the interactions of stars, clusters, planetary nebulae and galaxies. These factors make it a target system of interest to us. Visual survey of Magellanic Clouds system (VMC) survey is a survey project of the European Southern Observatory for the Magellanic Clouds system, which provides the near infrared observation images of the three bands of the Magellanic Clouds system (VMCs) for the Magellanic Clouds nebula. The observed images cover the major regions of the large and small Magellanic Nebula, their interconnected parts and some of the star flow regions. This is the most extensive survey of the Magellanic Nebula. As an important part of the VMC-survey project, the survey data is provided by Visa data processing system (pipeline), which processes the original observation images, including point source target extraction, photometry and final source table. Because the survey data processing system (pipeline) is based on the design of common scientific research target, it is not aimed at the dark source. Many researches require more accurate dark end data, and the data has a lower limit in a certain degree of completeness, but the processing results of the survey data processing system can not meet this requirement. In order to solve this problem, we selected the VMC completed survey area, through the processing of the original data, combined the survey data of many periods, manually carried out PSF photometry, obtained our latest source table, and then analyzed. The performance of the whole data in the dark end is described in detail. Finally, a set of data processing methods for the research of the dark end objects are provided. Our results are described as follows: 1. There is no systematic change of point diffusion function in the study region. 2. The performance of aperture photometry and point diffusion function photometry in processing VMC survey data and their differences to dark sources. 3. The difference between the new source table and the pipeline is that the photometry accuracy is higher, and the number of effective sources at the dark end is at least 30% higher (depending on the band, observation region) 4. Completeness curve with change of position. 5. Luminosity function of different star density regions.
【学位授予单位】：中国科学院研究生院（云南天文台）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P157

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