Krumholz Mark R, Klein Richard I, McKee Christopher F, Offner Stella S R, Cunningham Andrew J
Department of Astronomy, University of California, Santa Cruz, CA95064, USA.
Science. 2009 Feb 6;323(5915):754-7. doi: 10.1126/science.1165857. Epub 2009 Jan 15.
Massive stars produce so much light that the radiation pressure they exert on the gas and dust around them is stronger than their gravitational attraction, a condition that has long been expected to prevent them from growing by accretion. We present three-dimensional radiation-hydrodynamic simulations of the collapse of a massive prestellar core and find that radiation pressure does not halt accretion. Instead, gravitational and Rayleigh-Taylor instabilities channel gas onto the star system through nonaxisymmetric disks and filaments that self-shield against radiation while allowing radiation to escape through optically thin bubbles. Gravitational instabilities cause the disk to fragment and form a massive companion to the primary star. Radiation pressure does not limit stellar masses, but the instabilities that allow accretion to continue lead to small multiple systems.
大质量恒星产生的光如此之多，以至于它们对周围气体和尘埃施加的辐射压力比其引力吸引更强，长期以来人们一直认为这种情况会阻止它们通过吸积增长。我们展示了一个大质量恒星前核心坍缩的三维辐射流体动力学模拟，发现辐射压力并不会阻止吸积。相反，引力和瑞利 - 泰勒不稳定性通过非轴对称盘和细丝将气体引导到恒星系统上，这些盘和细丝对辐射进行自我屏蔽，同时允许辐射通过光学薄气泡逃逸。引力不稳定性导致盘碎裂并形成一颗大质量伴星围绕主恒星。辐射压力并不限制恒星质量，但允许吸积继续的不稳定性会导致形成小型多星系统。
