Systematics Searches for Brown Dwarfs and Planets

2004财年是这项资助的最后一年，我们通过在学术期刊上发表文章和在与棕矮星研究相关的国际研讨会上发表邀请论文，将我们的科学成果公之于众。首先，在光谱分类与棕矮星有效温度的关系上，我们发现光谱类型在L晚期和T早期之间的有效温度是恒定的（Nakajima, Tsuji, and Yanagisawa 2004,ApJ）。其次，我们从大气模拟的角度解释了光谱特征的变化（Tsuji, Nakajima & Yanagisawa 2004,ApJ）。第三，从2004年8月开始，我们已经开始用斯巴鲁系统地搜索棕矮星和行星，它的中期报告已经作为邀请论文在西班牙拉帕尔马举行的“超低质量恒星形成”研讨会上发表。这篇受邀论文的内容将于2005年12月发表在欧洲期刊《天文学笔记》上。褐矮星曾经是盘状暗物质的候选者，从内部物理学的角度来看，演化的褐矮星是低温简并恒星，由电子简并压力支持。作为棕矮星内部物理学的一个应用，我们已经证明，如果主导暗物质由ev质量的费米子组成，那么星系团中心的平顶密度分布可以用轻费米子的简并压力来解释（Nakajima & Morikawa 2005，ApJ提交）。最后，在2005年8月，我们整理了三年资助期间的科学成果，出版了一本小册子，总结了我们的工作。小册子的尺寸为A4，共有153页。

FY2004 is the last year of this grant and we have made our scientific results public by articles in academic journals and by an invited paper at an international workshop relavant to brown dwarf research. First, as to the relation between the spectral classification and effective temperature of brown dwarfs, we have found constancy of effective temperature between spectral types late L and early T (Nakajima, Tsuji, and Yanagisawa 2004,ApJ). Second, we interpretated the variation of spectral features from the point of view of atmospheric modeling (Tsuji, Nakajima & Yanagisawa 2004,ApJ). Third, we have started a systematic search for brown dwarfs and planets using Subaru, beginning August 2004,and its interim report has been presented as an invited paper at the workshop on "Ultra Low Mass Stars Formation" workshop held at La Palma, Spain. The content of the invitated paper is going to be published in an European refereed journal, Astronomical Notes in December 2005. Brown dwarfs used to be a candidate for disk dark matter and from the point of view of internal physics, evolved brown dwarfs are low temperature degenerate stars, supported by electron degeneracy pressure. As an application of brown dwarf interior physics, we have shown that if dominant dark matter consists of eV-mass fermiqns, the flat-top density profile of the center of a cluster of galaxies can be explained by degeneracy pressure of the light fermions (Nakajima & Morikawa 2005,ApJ submitted). Finally in August 2005,we have compiled the scientific results over the 3 year grant period and published a booklet, summarizing our work. The size of the booklet is A4 and it consists of 153 pages.