星間分子雲において形成される星の最大質量の観測的研究

关于恒星形成的研究大多是针对单个恒星形成区域进行的详细研究。这类研究往往是在猎户座KL区这样的“著名”恒星形成区进行的。然而，至关重要的是，要问这样的研究得出的性质是如何在恒星形成的其他区域中普遍存在的。在使用这些结果或将所得结论推广到恒星形成区域时，我们需要起到关键作用。本研究旨在利用名古屋大学研制的两台配备世界上最好的超导接收器的4米射电望远镜，通过对分子云、恒星形成区的广泛调查，了解恒星形成的趋势或恒星形成的一般规律。主要结论如下：1.云质量谱可以很好地表示为指数为1.7.2的幂定律。2.云质量与谱线宽度之间没有显著的相关性。3.单个云中形成的原恒星服从光度指数为-1，3的光度定律，这与已知的普通恒星的初始质量函数是一致的。4.在给定质量的云中形成的恒星的最大光度与母云质量的1，4次方成正比。4.恒星形成活动与云的维里质量和LTE质量之比有关。这一趋势自然被理解为表明云通过内部湍流运动的消散而慢慢收缩为恒星。

Studies of star formation have been made mostly as detailed ones for individual star forming regions. This kind of study tends to be done on "famous" star forming regions like Orion KL region. It is however crucially important to ask how the properties derived by such studies are ubiquitous among other regions of star formation. We need to be critical in using these results or extending the conclusions obtained to star forming regions in general. The present study aims at understanding the trend of star formation, or the general rule in star formation by carrying out an extensive survey of molecular clouds, star forming regions, with two 4-m radio telscopes equipped with the world-best superconducting receivers developed at Nagoya University.The major conclusions are summarized as follows ;1.The cloud mass spectrum is well represented as a power law of an index of 1.7.2.There is no significant correlation between the cloud mass and the spectral linewidth.3.The protostars formed in the individual clouds obeys a power law of luminosity with an index of-1,3, as is consistent with previously known Initial Mass Functions of ordinary stars.4.The maximum stellar luminosity formed in a cloud of a given mass is proportional to the 1,4-th power of the parent cloud mass.4.Star formation activity is correlated with the ratio of virial mass and LTE mass of a cloud. This trend is naturally understood as indicating that a cloud slowly contracts to for stars through dissipation of the internal turbulent motion.