Measurement of size of super massive black holes through observation of X-ray variabilities

这项研究的目的是研究活动星系核(AGN)的X射线变率，以估计它们的基本性质，如居住在其中的黑洞质量。我们还研究了活动星系核通过X射线变异性和光谱产生辐射的物理机制。我们的目标范围从低亮度活动星系核、塞弗特类型1和类型2、射电星系和Blazers1。我们提出用X射线变率的功率谱来衡量黑洞的大小，即黑洞质量。我们最初将这个方案应用于明亮的Seyfert 1星系，但将其扩展到各种类型的活动星系核，包括亮度最低的Seyfert 1星系NGC4395、Seyfert 2星系NGC6300。在这些情况下，功率谱形状类似于明亮的塞弗特1星系和恒星质量黑洞，表明共同机制在这些吸积黑洞中工作。NGC4395的黑洞质量估计为数万太阳质量，介于恒星质量黑洞和超大质量黑洞之间，是黑洞演化模型的重要组成部分。2.详细研究了Ark564、MCG-6-30-15和多个源的X射线强度和光谱的变化。铁发射线通常被解释为来自黑洞附近的荧光线，但为MCG-6-30-15提出了替代模型。X射线和其他波长数据的变化表明，这些来源的喷流发生的物理机制。我们发现内激波对于解释火焰中某些耀斑的光谱演化是很重要的。3.我们可以利用X射线变率作为一种工具来估计黑洞的大小，但造成这种变率的原因和物理机制尚不清楚。这将是我们研究的下一步。

This research project is aimed to study X-ray variability of Active Galactic Nuclei (AGN) in order to estimate their fundamental properties, such as masses of black holes residing them. We also study physical mechanism to generate radiation from AGNs through X-ray variability and spectra. Our targets range from low luminosity AGNs, Seyfert type 1 and type 2, radio galaxies, and blazers.1. We proposed to use the power spectra of X-ray variability as a measure of black hole size, namely black hole mass. We originally applied this scheme to bright Seyfert 1 galaxies, but extend it to various types of AGNs, including the lowest luminosity Seyfert 1 galaxy NGC4395, Seyfert 2 galaxies, NGC6300. In these cases, the power spectral shape is similar to that for bright Seyfert 1 galaxies and stellar mass black holes, indicating commmon mechanism is working in these accreting black holes. Black hole mass of NGC4395 is estimated to be tens of thousand Solar mass, which is intermediate between stellar mass black holes and super massive black holes and important for models for black hole evolution.2.Variabilities in X-ray intensity and spectra were studied in detail in several sources, including Ark564, MCG-6-30-15, and many blazers. Iron emission line is usually interpreted as a fluorescent line from the vicinity of a black hole, but alternative models proposed for MCG-6-30-15. X-ray and other wave length data on variabilities of blazers indicate physical mechanism occurred in jet from these sources. We show internal shock is important to explain the spectral evolution of some of the flares in blazers.3.We thick we can use X-ray variability as a tool to estimate black hole size, but the origin and physical mechanism that makes the variability is still unclear. That will be the next step for our study.