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A comprehensive study of dark halo with a large CCD camera

利用大型 CCD 相机对暗晕进行综合研究

基本信息

批准号：
11694071
负责人：
MURAKI Yasushi
金额：
$ 10.5万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11694071/
关键词：
gravitational microlensing Magellanic cloud black hole extra-solar planet EAGLE event long-period variables dark matter difference imaging analysis 重力レンズ CCDカメラ地球型惑星ガンマ線バースト星の大量連続測光

项目摘要

It is now well known that the Universe is filled with 'dark' matter. In order to investigate dark matter in the form of black holes and small low luminosity stars as well as to detect extra-solar planets, we have set up the MOA collaboration together with astronomers in New Zealand. We use the phenomenon of gravitational micro-lensing to detect such objects by observing the variations of the brightness of field stars produced by intervening dark, massive objects. See http : //www.vuw.ac.nz/scps/moa/.To date we have observed 4.4 million stars in the Large Magellanic cloud, 930 thousand stars in the Small Magellanic Cloud and 5.9 million stars in the bulge of our own galaxy. As a result of these observations, which have involved the analysis of enormous amounts of data by our group, we have :1) discovered a very interesting event in which the light intensity from a star increased over a period of 80 days, suggesting (with 40% probability) that a black hole was involved ;2) found indicati … More ons for the presence of one or even two Earth-sized planets close to a lens star and published the results in the Astrophysical Journal (this may be the first observation of such small planets and was given wide publicity in New Zealand and Japanese news media - radio TV and newspapers) and have shown that most planetary systems do not contain Jupiter-like planets ;3) developed a new method of data analysis based on a differential imaging technique which has been used since May 2000 to issue alerts of possible candidates for micro-lensing events to the world-wide astronomical community. This has been much appreciated since the MACHO collaboration stopped their alerts in 1999 and only MOA can observe the Large Magellanic Cloud in winter time ;4) have found examples of so-called EAGLE events, which differ from the usual gravitational lensing by their sharply-rising light curve, and which provide greater sensitivity for dark matter and planet detection.5) confirmed the existence of the overtone pulsators in Mira variables in the Large Magellanic Cloud and are now examining their nature together with appropriate magnitude and color calibrations.In future, in order to obtain much better information on the dark matter problem and to learn more about extra-solar planets and their formation, it will be necessary to introduce a 1.5 metre, f=4 telescope into the program. Less

现在大家都知道宇宙充满了“暗物质”。为了研究以黑洞和小的低光度恒星形式存在的暗物质，以及探测太阳系外行星，我们与新西兰的天文学家共同建立了MOA合作项目。我们利用引力微透镜现象，通过观察由暗的大质量天体介入而产生的场星亮度的变化，来探测这类天体。到目前为止，我们已经观测到大麦哲伦星云中的440万颗恒星，小麦哲伦星云中的93万颗恒星和银河系凸起部分中的590万颗恒星。我们小组对大量数据进行了分析，根据这些观察结果，我们发现了：1)发现了一个非常有趣的事件，一颗恒星发出的光强度在80天的时间里增加了，这表明（有40%的可能性）这与黑洞有关；2)发现了更多证据，证明在一颗透镜星附近存在一颗甚至两颗地球大小的行星，并在《天体物理学杂志》（Astrophysical Journal）上发表了结果（这可能是第一次观测到这样的小行星，并在新西兰和日本的新闻媒体——广播电视和报纸上得到了广泛的宣传），并表明大多数行星系统不包含类似木星的行星；3)开发了一种基于差分成像技术的数据分析新方法，该技术自2000年5月以来一直用于向全球天文学界发出微透镜事件可能的候选警报。自从1999年MACHO合作停止了他们的警报，只有MOA可以在冬季观测大麦哲伦星云以来，这一点一直很值得赞赏；4)发现了所谓的EAGLE事件的例子，它与通常的引力透镜不同，因为它的光线曲线急剧上升，并且为暗物质和行星探测提供了更高的灵敏度。5)在大麦哲伦星云的Mira变星中证实了泛音脉动的存在，现在正在通过适当的星等和颜色校准来研究它们的性质。未来，为了获得更多关于暗物质问题的信息，并了解更多关于太阳系外行星及其形成的信息，有必要在该计划中引入一个1.5米，f=4的望远镜。少