Research On The Explosion Mechanism Of Type II Supernovae

In this paper, physical process in presupernova and prompt explosion mechanism oftype II supernova (SNII) are investigated.The research progress relevant to explosion mechanism is summarized. Including theevolution of massive stars, the reason of causing collapsing instability in stars . The classifycharacters of SN and the structure of prosupernova are introduced,especially the prosuper-nova given by Woosley after 2000. The main SNII explosion mechanisms and the di?culty inthe theory research are reviewed. The physical factors relevant to SNII explosion numericalsimulation and numerical simulation methods are introduced, which include nuclear statis-tical equilibrium(NSE), electron capture (EC),four model state equation, general relativityhydrodynamic method,numerical simulation methods.We make a discussion in detail aboutthe e?ect of new presupernova on the core collapse, shock propagation , explosion energyand the definition of initial explosion energy.Presupernova and the structure of inner core are very important to supernova explosion,which sensitivity to the physical parameters given by presupernova, the physical parameterhave a great e?ect on the condition and the results of supernova explosion.Here we restudythe e?ect of presupernova on the core collapse, shock propagation and explosion energy,usingthe data of presupernova given by Wooley in 2002,and also make a discussion about the defi-nition of initial explosion energy.The results of this paper show that the collapse time(τc(o1l)lap)of supernova models,which presupernova are 11M , 12M and13M ,is reduced for the changeof initial density.While the collapse time of the model using 15M presupernova is delay.In addition,the inner densityρmcaxand the Ms of the four models are all augmented,whichwill be good to shock propagation. The augmentation of Ms shorten the distance of shockpropagation,and the augmentation of inner density made the rebound more powerful. Fromthe comparison of the two models ,which presupernova are 11M and 12M ,we find thatthe augmentation of initial temperature will make the collapse more rapid.In the process ofshock propagation, the new models run faster first and then become slow ,comparing to themodels of Wang,while the transmission time is appropinquity .Furthermore, the shock energyis augmented for the increase of inner binding energy (?EbH )and the decrease of energy usedfor photodisintegration(Edis) and the decrease of neutrino loss(?Eν).And we use 12 mod-els to discuss the definition of initial shock energy ,found that the definition of Es(h4)ock and Es(h5)ock are more suitable than others. The above conclusions show that new presupernovahave a great e?ect on the core collapse, shock propagation and explosion energy.And it issignificance for the theoretical research of supernova.