Formation of Massive Black Holes in an Early Universe and Cosmological Consequences

研究了宇宙背景辐射(CBR)在宇宙复合后不久对早期形成天体的辐射力的影响。在假定圆盘局部近似为纵向运动的平面平行介质的情况下，通过求解考虑Thomson散射的辐射传递方程计算了CBR的辐射力。结果表明，即使辐射扩散是有效的，CBR对角动量的提取效率也随光学厚度呈指数下降。由于目前的效应，在强CBR的存在下，早期形成的盘的自旋几率的分布可能被显著地改变。此外，CBR力可能有助于增强切变粘性的影响，从而使z&gt；10处的种子黑洞能够解释类星体的形成。此外，我们还研究了一群遗留的大质量黑洞的可能性，可能构成一个重要的COM…更多的暗物质成分，可能是通过它们偶尔对遥远外部星系中的个别发光恒星进行非常强烈的引力透镜来间接探测到的。对于合理的、在某些方面保守的相关物理参数值，我们表明，这种事件可能在达到常规CCD震级限制的广域调查(如斯隆数字天空调查)中探测到，也可能在小视场、非常深的图像中探测到(如HDF)。因此，探测或限制宇宙中大量残留的大质量黑洞将是一项具有挑战性的任务。此外，我们提出了一种新的为活动星系核(AGN)提供燃料的机制，即辐射雪崩，这是由来自核周恒星爆发区域的恒星辐射所产生的辐射阻力所驱动的质量吸积。如果旋转气体盘的表面层受到强烈的星光照射，那么它可能会通过辐射阻力失去角动量，从而不可避免地导致层的雪崩。分析表明，在光学厚区，这种辐射雪崩的质量吸积率不仅与光子吸收物质的消光系数有关，还与星盘的密度分布有关，最大质量吸积率可用M-L_m/c^2简单描述，L_m为星暴的测辐射光度。在目前的背景下，辐射雪崩的强度决定了一个星暴星系是否注定拥有活动星系核。本模型提供了一个从第一原理推导出来的坚实的物理机制，以解释恒星爆发活动和活动星系核之间可能的联系，这已经被许多观测所表明。较少

The effects of radiation force by the cosmic background radiation (CBR) on early-formed objects shortly after the cosmological recombination have been explored. The radiation force by the CBR is calculated by solving radiative transfer equation with including Thomson scattering, under an assumption that a disk is locally approximated to be a plane-parallel medium in longitudinal motion. The results show that the efficiency of angular momentum extraction by the CBR decreases exponentially with optical depth even if the radiative diffusion is effective. Bacause of the present effects, the distributions of the spin probability of early-formed disks could be significantly modified in the presence of the strong CBR.Also, the CBR force likely helps to enhance the effects of shear viscosity, thereby enabling a seed black hole form at z>10 to account for quasar formation.Also, we have examined the possibility that a population of relic massive black holes, perhaps constituting an important com … More ponent of the dark matter, might be indirectly detected via their occasional very strong gravitational lensing of individual luminous stars in distant external galaxies. For plausible, and in some respects conservative, values of the relevant physical parameters, we show that such events might be detected either in wide area surveys reaching routine CCD magnitude limits (such as the Sloan Digital Sky Survey) or in small field, very deep images (such as the HDF). Thus, it would be a challenging but not impossible task to detect or place limits on a cosmic population of relic massive black holes.Furthermore, we have proposed a novel mechanism for fuelling active galactic nuclei (AGNs), i.e., a radiative avalanche, which is mass-accretion driven by radiation drag exerted by stellar radiation from circumnuclear starburst regions. If a surface layr of a rotating gas disk is irradiated by intensive starlight, then it could lose angular momentum via radiation drag, resulting in an avalanche of the layr as an inevitable consequence. Analyzes show that in an optically thick regime, the mass-accretion rate via this radiative avalanche is in dependent of not only the extinction coefficient of photon absorbing matter but also the density distribution of the disk, and the maximal mass-accretion rate is simply described as M-L_m/c^2 with L_m being the bolometric luminosity of a starburst. In the present context, the intensity of radiative avalanche determines whether a starburst galaxy is destined to posses an AGN or not. The present model provides a solid physical mechanism deduced from first principles to account for the possible link between starburst activities and AGNs, which has been suggested by a number of observations. Less