Study On The Spectral Lag Of Gamma-ray Bursts Based On Large Sample

Gamma-ray bursts are short-term outburst of gamma rays detected by high-energy satellites in the distant universe.They are closely related to astrophysical phenomena such as supernova explosions,compact star mergers,stellar black holes and gravitational wave bursts,and are currently one of the most hot topics in the astrophysics.With the increase of observed phenomena,the observation law of multi-band radiation becomes more complicated and changeable.In particular,there are many difficult problems to be solved in the physical origin,burst mechanism,observation search and authentication classification of the prompt gamma ray radiation.In recent years,HXMT,GECAM and other high-energy space satellites have been launched and put into use,and a number of related satellite projects are under close preparation.In this era of data science,how to analyze and process a large amount of satellite observation data,reasonably deduct the complex and changeable background noise of space radiation,and rapidly verify and classify the information of gamma-ray bursts,it is an important problem in the current observation research.In this paper,we will select a group of high signal to noise ratio samples from more than 2,000 gamma ray bursts observed over twelve years by Fermi Gamma-ray Space Telescope,this paper studies the spectral lag of the most representative samples,trying to summarize the spectral lag law of gamma-ray bursts,and to provide up-to-date observational basis for the observational verification and physical classification of gamma-ray bursts.This thesis is divided into five chapters.In the first chapter,we introduce the background of gamma-ray bursts and the questions.The second chapter is a brief introduction to the sample selection process and Fermi Gamma-ray Space Telescope.The third chapter introduces several methods used in this paper: Bayesian blocks,CCF and Bootstrap methods.The fourth chapter is the detailed calculation process of spectral lag and the result of spectral lag and partial data analysis.The fifth chapter is the summary of the whole paper and the prospect of the future.The main conclusions are as follows(1)In the 99 gamma-ray bursts samples,after systematic analysis of the data,the changes of spectral lag in the adjacent energy intervals show positive delay behavior;(2)Spectral lag as long as radiation duration,the longer the spectral lag,the longer the duration is.