Radiation Hydrodynamical Mass Accretion onto Galactic Nuclei Driven by Circumnuclear Starbursts
Radiation Hydrodynamical Mass Accretion onto Galactic Nuclei Driven by Circumnuclear Starbursts
复制标题
环核星暴驱动的星系核辐射流体动力学质量吸积
DOI：
10.1093/pasj/51.3.345
复制
发表时间：
1999
影响因子：
2.3
通讯作者：
S. Mineshige
中科院分区：
文献类型：
--
作者：
K. Ohsuga;M. Umemura;J. Fukue;S. Mineshige
我们探索了银河系核气盘在周围核星暴强辐射下的辐射流体动力学演化。这一演变过程分为两个阶段。首先，圆盘受到辐射力的径向收缩。随后，由于辐射阻力去除角动量，圆盘的表面层向中心雪崩。在假定环核星爆区为环状的情况下，定量分析了辐射驱动的雪崩所产生的质量吸积。结果发现，质量吸积率敏感地依赖于恒星暴发区的扩展。对于光学厚度的圆盘，质量吸积率大致与圆环的厚度与曲率半径之比成正比。该速率还取决于圆盘的旋转定律。我们研究了由辐射驱动的质量吸积引起的盘表面密度的演化。结果发现，强度越大的星暴，表面密度的中心集中越明显。当考虑到恒星爆发核的演化时，例如在发光的IRAS星系中，目前的结果似乎是重要的。
We explore the radiation hydrodynamical evolution of a galactic nuclear gas disk exposed to intense radiation from circumnuclear starbursts. The evolution is characterized by two stages. First, the disk is radially contracted by the radiation force. Subsequently, the surface stratum of the disk avalanches onto the center due to the removal of angular momenta by radiation drag. The mass accretion via a radiatively driven avalanche was analyzed quantitatively while assuming a torus shape of the circumnuclear starburst regions. As a result, it was found that the mass-accretion rate is sensitively depenoent upon the extension of the starburst regions. For an optically thick disk, the mass-accretion rate is roughly in proportion to the ratio of the thickness to the curvature radius of the torus. The rate is also dependent upon the rotation law of the disk. We investigated the evolution of the disk surface density resulting from radiatively-driven mass accretion. It was found that for a more intensive starburst the central concentration of surface density becomes more conspicuous. The present results seem to be significant when considering the evolution of starburst nuclei, for instance, in luminous IRAS galaxies.