Infrared Observation of Galactid Halo

宇宙中的暗物质是现代天文学最重要的课题之一。这项研究的目的是寻找低质量恒星对星系暗物质的贡献。火箭有效载荷是在美国人的合作下研制的。1996年6月和1997年5月在白沙利用美国国家航空航天局的探空火箭进行了火箭实验，成功地获得了外星系NGC4565的第一张红外图像。对所获得的数据进行了仔细的分析，得出了以下新的结果。从中心5‘处探测到了扩展发射分量。该发射分量显示的r^&lt；-3.6；依赖关系不同于从平坦旋转曲线预期的r^&lt；-1&gt；依赖关系。通过与由旋转曲线估算的质量分布进行比较，得到质量与光度比M/L在3.5-5微米时的下限为^-300。这个值表明，如果暗物质由点源组成，普通恒星不可能是暗物质，褐矮星很可能是暗物质的起源。另一方面，最近的MACHO实验表明，MACHO的质量为^-0.5M_0(不小于0.10.1M_0)，一半的暗物质可以用MACCO解释。我与MACO实验一致的暗物质的可能候选者和我们的结果现在是白矮星和黑洞，尽管它们的起源仍然是问题。

Dark matter in the Universe is one of the most important topics of the modern astronomy. The purpose of this research is to find the contribution of low mass stars to the galactic dark matter.The rocket payload was developed under the collaboration with US people. The rocket experiments were carried out on June 1996 and May 1997 at White Sands with using sounding rocket of NASA.The first infrared image of the external galaxy NGC4565 was successfully obtained.The obtained data were analyzed carefully, and following new results were delineated.The extended emission component was detected over 5'from the center. This emission component shows r^<-3.6> dependence that is different from r^<-1> dependence expected from the flat rotation curve. By comparing with mass distribution estimated from the rotation curve, lower limit of ^- 300 was obtained for the mass to luminosity ration, M/L,at 3.5-5mum. This value indicates that ordinary stars can not be dark matter and brown dwarfs are likely to be origin of the dark matter if dark matter consists of point sources.On the other hands, recent experiments of MACHO indicate that the mass of MACHO is ^-0.5M_0 (not less than 0.10.1M_0) and half of the dark matter can be explaened by MACHO.The possible candidates of the dark matter that iare consistent both with MACHO experimints and our result are now white dwarfs and black holes, although their origins are still remaind to be problems.