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

• 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

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

现在众所周知，宇宙充满了“暗”物质。为了研究黑洞和小型低光度恒星形式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建立了MOA合作。我们利用引力微透镜现象，通过观察由黑暗的大质量物体所产生的场星亮度的变化来探测这样的物体。参见http：//www.vuw.ac.nz/scps/moa/.To日期，我们已经观察到大麦哲伦星云中的440万颗恒星，小麦哲伦星云中的93万颗恒星和我们银河系凸起中的590万颗恒星。通过这些观测，包括我们小组对大量数据的分析，我们发现：1）发现了一个非常有趣的事件，其中一颗星星的光强度在80天内增加，这表明（40%的可能性）涉及黑洞;2）发现了一个新的黑洞。 ...更多信息 他们认为在一颗透镜星星附近存在一颗甚至两颗地球大小的行星，并将结果发表在《天体物理学杂志》上（这可能是第一次观察到这种小行星，并在新西兰和日本的新闻媒体-广播电视和报纸上进行了广泛宣传），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，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候选者的警报。自从1999年MOA合作停止了他们的警报以来，这一点得到了很大的赞赏，只有MOA可以在冬季观测大麦哲伦云; 4）已经发现了所谓的EAGLE事件的例子，它与通常的引力透镜不同，因为它们的光变曲线急剧上升，并为暗物质和行星探测提供更高的灵敏度。天文台证实大麦哲伦星云中的米拉变星存在泛音变星，目前正在研究它们的性质，并进行适当的星等和颜色校准。今后，为了获得有关暗物质问题的更好信息并更多地了解太阳系外行星及其形成，有必要在该计划中引入一台1.5米、f=4的望远镜。少

项目成果

T.Yanagisawa et al.: "Wide-Field Camera for Gravitational Microlensing Survey : MOA-CAM 2"Experimental Astronomy. 10. 519-535 (2000)

T.Yanagisawa 等人：“用于引力微透镜巡天的广角相机：MOA-CAM 2”实验天文学。

T.Sumi: "Constraining the location of microlensing objects by finite source effect in EAGLE events"Astro.Phys.J.. (印刷中). (2000)

T.Sumi：“通过 EAGLE 事件中的有限源效应约束微透镜物体的位置”Astro.Phys.J.（出版中）。

T.Yanagisawa: "Wide field camera for gravitational microlensing surver: MOA-cam2"Experimental Astronomy. (印刷中). (2000)

T.Yanagisawa：“用于引力微透镜观测器的广角相机：MOA-cam2”实验天文学（2000 年）。

I.A.Bond et al.: "Study by MOA of Extra-Solar Planets in Gravitational Microlensing Events of High Magnification"Mon.Not.R.Astron.Soc.. (印刷中). (2001)

I.A.Bond 等人：“MOA 对高放大率微引力透镜事件中太阳系外行星的研究”Mon.Not.R.Astron.Soc.（出版中）。

F.Abe: "Observation of the halo of the edge-on galaxy IC5249"Astronomical J.. 118. 261-272 (1999)

F.Abe：“边缘星系 IC5249 光环的观测”《天文学杂志》118. 261-272 (1999)