Wilking B A
Department of Physics and Astronomy, University of Missouri-St Louis 63121, USA.
Orig Life Evol Biosph. 1997 Jun;27(1-3):135-55.
Recent evidence indicates that most low mass stars in the Galaxy (< 5 M [symbol: see text]) form alongside massive stars in clusters embedded in giant molecular clouds. Once their parental gas is removed, the fate of these clusters is to disperse and blend into the field population of the galactic disk. The distribution of stellar masses in the solar neighborhood, called the Initial Mass Function, is discussed in the context of the origin of low mass stars. Arguments based on the production rate of field stars are presented that point to giant molecular clouds as the primary birth sites for low mass stars. The role of observations of molecular clouds at millimeter and infrared wavelengths in confirming this picture is reviewed. Millimeter-wave observations have revealed that molecular clouds consist of low-density gas interspersed with high-density cores. Near-infrared images of these clouds indicate that stars form preferentially in these cores, with the number of young stars roughly scaling with the mass of the core. Molecular-line and near-infrared observations which characterize star formation in the nearest giant molecular cloud complex in Orion are presented. The implications for the Sun forming in a cluster environment are briefly discussed.
最近的证据表明，银河系中大多数低质量恒星（<5 M⊙）与嵌入巨分子云中的星团中的大质量恒星一起形成。一旦其母气体被移除，这些星团的命运就是分散并融入银河系盘的场星群体中。在低质量恒星起源的背景下，讨论了太阳邻域恒星质量的分布，即初始质量函数。基于场星产生率的论据表明，巨分子云是低质量恒星的主要诞生地。回顾了毫米波和红外波段分子云观测在证实这一图景中的作用。毫米波观测表明，分子云由低密度气体和高密度核心交织而成。这些云的近红外图像表明，恒星优先在这些核心中形成，年轻恒星的数量大致与核心质量成比例。介绍了表征猎户座中最近的巨分子云复合体中恒星形成的分子线和近红外观测结果。简要讨论了太阳在星团环境中形成的影响。
