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

对恒星形成的研究大多是对单个恒星形成区域的详细研究。这类研究往往是在“著名的”恒星形成区，如猎户座KL区进行的。然而，至关重要的是要问，这些研究得出的特性如何在其他恒星形成区域中普遍存在。在使用这些结果或将所得结论推广到一般的恒星形成区域时，我们需要非常谨慎。目前的研究旨在了解恒星形成的趋势，或恒星形成的一般规律，通过对分子云，恒星形成区域进行广泛的调查，使用两个4米射电望远镜，配备由名古屋大学开发的世界上最好的超导接收器。主要结论总结如下：1。云质谱很好地表示为指数为1.7.2的幂律。云量与谱线宽度之间没有显著的相关性。在单个星云中形成的原恒星遵循光度指数为-1,3的幂律，这与先前已知的普通恒星的初始质量函数是一致的。在给定质量的星云中形成的最大恒星光度与母星云质量的1.4次方成正比。恒星的形成活动与云的viri质量和LTE质量的比值有关。这种趋势自然地被理解为表明云通过内部湍流运动的耗散而缓慢地收缩为恒星。

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.