Study On The Bunching Effect Of TeV Blazar

Blazar is a class of objects with extreme observational features in active galactic nuclei.In the radio band,their emissions are composed of two components.In the high energy bands,Tera-electronvolts(TeV;1012electronvolts)emissions were detected from some blazars.Does the TeV emission of blazar also consist of two components?If so,how can it be divided into two components?Is there any connection or difference between the beaming effect in the radio band and that in the TeV band?we compiled a sample of 51 TeV blazars with available radio core dominance parameters and applied a two-component(the beamed and the unbeamed)model to study the composition of blazar TeV emission.To investigate the TeV beaming effect,we can further calculate and analyze the TeV core-dominance parameter of the blazars to explore the differences of the beaming effect between different types of TeV blazars.We obtained the core-dominance parameter at the TeV band through applying a relativistic beaming model,and found that the average TeV core-dominance parameter is log RTeVBL=<3.12±2.83>for 46 BLLacs,and that is logRTevFRSQ<4.80±1.76>for 5 FSRQs,which shows an indication that the core dominance parameter in BL Lacs is smaller than that in FSRQs.For the three subclasses of BL Lacs—high synchrotron peaked BL Lacs(HBLs),intermediate synchrotron peaked BL Lacs(IBLs)and low synchrotron peaked(LBLs),logRTeVHBL is smaller than logR/TeVIBL and logRTeVLBL.Our results suggest that the blazar TeV emission from the core is thousands times stronger than from the extended region and the TeV emission is more core-dominated for the lower synchrotron peaked sources.In addition,a significant correlation between the TeV core-dominance parameter(logRTeV)and the radio one(logRradio)logRTeV=(2.56±0.08)logRradio+0.99,is obtained suggesting that the TeV emission is beamed and the TeV core-dominance parameter is an indicator of beaming effect at the TeV bands,and that the TeV emission has stronger beaming effect than the radio emission.In future researches,we hope that with large telescopes and detectors,we can obtain a larger number of TeV blazar data with more complete information,and combine multi-band observations to further study the high-energy radiation and physical mechanisms of TeV blazars.