标题： 超音速湍流，丝状吸积和大质量恒星及盘的快速形成 显示英文标题

标题： Supersonic turbulence, filamentary accretion,and the rapid assembly of massive stars and disks

摘要： 我们对分子云中原恒星盘和大质量恒星的形成进行了详细的计算研究。 我们通过非常高分辨率的三维自适应网格细化（AMR）模拟，追踪了集群形成云块中大尺度丝状结构的演化，直至原恒星尺度，并展示了在这种环境中吸积盘和大质量恒星是如何形成的。 我们发现，一个最初呈拉长状态的云核，由于斜冲击产生的轻微旋转，首先坍缩成一条丝状体，随后在丝状体中心附近发展出湍流盘。 持续的大尺度流动与丝状体碰撞，维持了其中的高密度和高压。 冷却丝状体内的物质发生引力坍缩，并在外向内组装成一个大质量原恒星。 我们的模拟显示，这种丝状吸积导致了高达10^-2 Msol/yr的极高质量吸积率以及高超音速的下落速度。 以这些速率进行的吸积比半解析研究中发现的高出一个数量级，并可能抑制正在成长的大质量年轻恒星的辐射场。 我们的模拟包括一系列重要的化学和辐射过程，如分子谱线辐射冷却、气体-尘埃相互作用、光学厚区域的辐射扩散，以及H2的形成和解离。 因此，我们首次能够探测从云块特征到原恒星核的所有尺度的相关物理现象。 显示英文摘要

摘要： We present a detailed computational study of the assembly of protostellar disks and massive stars in molecular clouds with supersonic turbulence. We follow the evolution of large scale filamentary structures in a cluster-forming clump down to protostellar length scales by means of very highly resolved, 3D adaptive mesh refined (AMR) simulations, and show how accretion disks and massive stars form in such environments. We find that an initially elongated cloud core which has a slight spin from oblique shocks collapses first to a filament and later develops a turbulent disk close to the center of the filament. The continued large scale flow that shocks with the filament maintains the high density and pressure within it. Material within the cooling filament undergoes gravitational collapse and an outside-in assembly of a massive protostar. Our simulations show that very high mass accretion rates of up to 10^-2 Msol/yr and high, supersonic, infall velocities result from such filamentary accretion. Accretion at these rates is higher by an order of magnitude than those found in semi-analytic studies, and can quench the radiation field of a growing massive young star.Our simulations include a comprehensive set of the important chemical and radiative processes such as cooling by molecular line emission, gas-dust interaction, and radiative diffusion in the optical thick regime, as well as H2 formation and dissociation. Therefore, we are able to probe, for the first time, the relevant physical phenomena on all scales from those characterizing the clump down to protostellar core.