Systematics Searches for Brown Dwarfs and Planets

点击翻译按钮获取中文摘要

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.