Period04 Analysis Of Active Galactic Nuclei

Active galactic nuclei，or AGN，are peculiar galaxies which have energeticphenomena in the central regions. Some of the most important properties of AGN arethat they are star-like objects, have time-variable continuum flux, and the spectrainclude broad emission lines. Variability is a common phenomenon in AGN and isobserved over wide range from radio to X-ray. Some parameters and characteristics，such as optical variable optical variable time scale, time delay, etc., provides criticalinformation for people to understand the structure and physical processe of celestialcenter. This thesis focuses on analysis the variability periodicities of active galacticnucleus.The first chapter introduces the basic concepts of active galactic nuclei’sobserved characteristics, classification and its model. The second chapter is a briefintroduction of the AGN optical variable and model. Optical variable is a verycommon feature for AGN, observing and studing AGN periodic light variations is avery important way to get various properties of celestial bodies. The third chapterdescribes several methods which used to analysis the period of active galacticnucleus’s optical variable commonly, including power spectrum, wavelet analysismethod and Jurkevich. These types of period analysis methods have good applicationon analysis of AGN’s period of optical variable. The fourth chapter describes the mostbasic and most common method, spectral analysis--Fourier transform, and describesthe spectral analysis software Period04related to the Fourier transform and how touse the spectral analysis software Period04in analysis AGN’s period of opticalvariable. Due to weather, equipment and some other objective reasons, theobservational data are non-uniform. Period04use non-uniform sampling signalFourier transform. The fifth chapter describes the study of AGN’s period of opticalvariable with spectral analysis software Period04. We collected the observed data ofoptical variable about PKS1510-089at radio band of37GHz, the observed data ofoptical variable about OJ287at the optical B-band and V-band in30years and theobserved data of optical variable about S50716+714at the optical B, V, R and I band. We use spectral analysis software-Period04to analyze their period of optical variable,and obtain a reliable result. The application of Period04analysis method to analysisof AGN’s period of optical variable is successful.