Formation of Intermediate Mass Black Holes in Star Burst Galaxies

本研究的三点是：(1)高密度恒星系统中的恒星爆发现象；(2)恒星残骸的引力相互作用导致的中质量黑洞（IMBH）的形成；(3)中质量黑洞的引力相互作用导致的超大质量黑洞（SMBHs）的生长。这三个步骤可以划分为每个独立的过程。首先，在步骤(1)中，检查了恒星爆炸现象中形成的残余物。由于恒星黑洞和中子星太少而不能形成通常的质量函数，因此必须考虑更平坦的质量函数。在接下来的步骤(2)中，如果我们假设恒星残余物的分布与恒星分布相同，速度分布为通常的高斯分布，则由于远距离的两体引力相互作用，恒星残余物系统演化为核晕结构。很快，三体碰撞变得有效，残余系统向高密度系统演化。难题在于，由于绝热收缩，残余系统的收缩变得非常缓慢，以至于在10gy内无法形成黑洞。然后，在假设气体分量共存的情况下，考虑了气体阻力效应和超声速运动引起的激波耗散。然而，冷却效应太小，不足以影响进化。由此产生的残余系统半径为10pc，质量为100,000太阳质量。这个尺寸对于IMBH的形成来说太大了。对于步骤(3)，我们研究了在10 Gy范围内形成SMBH的条件。由此得出结论：IMBHs一定是由大小为1pc、质量为100万太阳质量的粒子聚集而成的。如果是这样，则(2)中形成的高密度残余系统的尺寸与形成SMBH所需的尺寸相差4位数，这一差距很难重合。因此，在从(2)到(3)的步骤中，我们必须包括一些在本工作中没有考虑到的新的物理过程。这个问题是今后研究的课题。少

As the three points of this research are set in the followings : (1)Star burst phenomena in high dense stellar systems, (2)Formation of intermediate mass black holes(IMBH)s due to the gravitational interaction of Stellar remnants, and (3)Growth to super massive black holes(SMBHs) due to gravitational interaction of IMBHs. These three steps can be divided to each independent process.At first in the step (1), it is examined what remnants are formed in a star burst phenomenon. Since stellar black holes and neutron stars are too few to form an IMBH for a usual mass function, it is shown that a flatter mass function must be considered. In the following step (2), if we assume the distribution of stellar remnants to be the same as stellar distribution and velocity distribution to be usual Gaussian distribution, the stellar remnant system evolved to the core-halo structure due to distant two-body gravitational interaction. Soon, the three-body collisions become effective and remnant system evo … More lved to high dense system. The difficult problem is that the contraction of remnant system becomes so slow because of adiabatic contraction that the IMBH can not be formed within 10 Gy. Then, assuming the co-existence of gas-component, we included the gas drag effects and the shock dissipation due to supersonic motions. However, the cooling effect is too small to affect the evolution. The resultant remnant system is the radius 10pc and mass 100,000 solar mass. This size is too large for the formation of IMBH. As for the step (3), we examined the conditions for the formation of an SMBH within 10 Gy. It is concluded that the IMBHs must be accumulated with size 1pc and mass 1 million solar mass. If so, the difference between the size of high density remnant system formed in (2)and the necessitated size for the formation of SMBH is 4 digits, this gap is very difficult to coincide. Therefore, in the step from (2)to (3), we must include some new physical processes which are not considered in this work. This problem is the subjects of future research. Less