Study On X-ray Variability Of GRS 1915+105

Black hole is one of the most mysterious and compact high-energy objects.The black hole X-ray binary(BHXRB)is composed of a stellar black hole and its companion star.The black hole accretes the material of the companion star and forms accretion disk,which mainly radiate at X-rays.One of the well-known sources GRS 1915 + 105 shows complex and variable energy spectrum as well as variability characteristics.The study on the spectrum and variability will help us understand accretion and relativistic jet models in astrophysics.We reduce the X-ray observations data from RXTE satellite and HXMT satellite to explore the variation in GRS 1915+105.In Chapter 1,we briefly introduce the basic properties of black holes,the basic theory and models of black hole X-ray binaries,including the accretion models.Then we present the radiation mechanism theory of black hole X-ray binaries.Finally,we introduce different states of black hole X-ray binaries and the main models to explain the energy spectrum of black hole X-ray binaries in different states.In Chapter 2,we introduce the specific black hole X-ray source GRS 1915 + 105,which is one of the most active and brightest sources in X-ray astronomy,and has complex energy spectrum and time-varying characteristics.In addition,its super luminal jet has been widely studied.Then its recent research progresses,including the mechanism of low-frequency quasi periodic oscillation,are introduced.Finally,the theory and numerical simulations of the most famous low-frequency quasi periodic oscillation signal state are presented.In Chapter 3 we introduce the basic introduction of HXMT and RXTE satellites,its data files and data reduction.In Chapter 4,we present the process of the transition from ? class oscillation to ?class oscillation in the short-term scale observed by RXTE for GRS 1915 + 105 and we successfully presented ? class oscillation by simulation.In addition,in order to study the complex light curve of GRS 1915+105.The waiting time and burst luminosity of each small burst in the light curve and the relationship between them are explored.We found that there is a good positive correlation between the waiting time and burst luminosity in the light curve of ? class oscillation,which is consistent with the results of previous work on oscillation signals generated by the simulation of accretion disk instability in stellar black holes.With the data from HXMT satellite for GRS 1915+105,a new class of oscillation is found.We further explore the variability properties in this new state with analysis on the hardness ratio and power density spectrum.A new model independent analysis method called stepwise filtering correlation analysis method is introduced which can help to find out its different periodic ingredients.Finally,the longtime scale light curve variation and energy spectrum of HXMT observation data are analyzed,and the uniqueness of GRS 1915 + 105 is discussed in combination with HXMT data.In last chapter,we summarize our main results and discuss possible future work.