A Comprehensive Statistical Study On Prompt Emission,afterglow And Host Galaxy Of Gamma-ray Bursts

Gamma-ray bursts(GRBs)were detected firstly in 1967 by the Vela Satellite Network.Since 1990 s,GRBs have been intensely studied.GRBs are the most violent and energetic stellar explosions known to humankind in distant galaxies.Even though many researches during many years,the nature of GRBs is still unclear.One of the historical models used to explain the GRB phenomenon is the “fireball” model.Nowadays,there are many statistical works and many kinds of theoretical models,in order to reveal the GRB underlying physics.It suggests that GRBs are produced by a highly relativistic,collimated jets.The main direction of this thesis is collecting a complete GRB sample(including 6289 GRBs with basic information and 46 parameters)and providing the primary statistical results.Then we give the detailed correlation analysis of host galaxy offset with GRB duration and energy.Lastly we give the statistical result of Amati correlation for short GRBs,in order to determine the Lorentz factor and viewing angle of GRB 170817 A.This work involves the data analysis of different GRB parameters and some statistical knowledge.The thesis is structured as follows: In Chapter I,we introduce the observations of GRBs,prompt emission,afterglow,host galaxy,and some existing statistical works.In Chapter II,we introduce the details of our big table,including data collecting,the details of every parameter,data processing,statistical methods and primary results.Because there are many primary results,we just show a small part of our primary results in this thesis.Our big table is the most complete sample until now.It is very important for comprehensive GRB statistics.We apply some statistical methods,especially the multiple imputation method for dealing with missing errors.In Chapter III,we give the detailed correlation analysis of GRB host galaxy offset with GRB duration andenergy.We found offset has negative correlations with duration and energy.It might due to different progenitors of short GRBs(SGRBs)and long GRBs(LGRBs).The progenitor of LGRBs is most-likely massive star collapsar,while two compact stars merger for SGRBs.For SGRBs,offset still has negative correlations with energy,not for LGRBs.It implies that the progenitors of SGRBs might have more subgroups.The two subgroups might be neutron star(NS)-black hole(BH)merger or NS-NS merger.We put the special GRB 170817 A and GRB 060218 A on our plots.The two GRBs both have low luminosity and small offset.The two GRBs are outliers in most of our plots,and might imply more subgroups of GRB samples.In Chapter IV,we give the statistical result of Amati correlation for SGRBs.We determine the Lorentz factor and viewing angle of GRB 170817 A.The Doppler factor and the luminosity follow a universal relation from GRBs and blazars,which indicates they may share similar radiation mechanism,and we found GRB 170817 A locates in the blazar side.In Chapter V,we summarize our work,the problems in all the works and the prospect of the future works.This thesis provides the most complete GRB samples and many primary results.Then we give the detailed correlation analysis of host galaxy offset with GRB duration and energy.Lastly we give the statistical result of Amati correlation for short GRBs,in order to determine the Lorentz factor and viewing angle of GRB 170817 A.