Modeling the radio and optical/NIR afterglows of GRB 980703:A numerical study  

作　　者：CHENG KwongSang 

机构地区：[1]Department of Physics,The University of Hong Kong

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第12期2047-2053,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 10625313 and 10973039);the National Basic Research Program of China (Grant No. 2009CB824800);a GRF Grant of Hong Kong Government (Grant No. HKU701109P)

摘　　要：Extensive multi-band afterglow data are available for GRB 980703. Especially,its radio afterglow was very bright and was monitored until more than 1000 days after the trigger time. Additionally,there is no obvious special feature,i.e.,no rebrightenings,no plateau,and no special steep decay or slow decay in the multi-band afterglow light curves. All these conditions make GRB 980703 a precious sample in gammaray burst research. Here we use the observational data of GRB 980703 to test the standard fireball model in depth. It is found that the model can give a satisfactory explanation to the multi-band and overall afterglow light curves. The beaming angle of GRB 980703 is derived as ～ 0.23 radian,and the circum-burst medium density is ～ 27 cm-3. The total isotropic equivalent kinetic energy of the ejecta is ～ 3.8 × 1052 ergs. A rest-frame extinction of AV ～ 2.5 mag in the host galaxy is also derived.Extensive multi-band afterglow data are available for GRB 980703. Especially, its radio afterglow was very bright and was monitored until more than 1000 days after the trigger time. Additionally, there is no obvious special feature, i.e., no rebrightenings, no plateau, and no special steep decay or slow decay in the multi-band afterglow light curves. All these conditions make GRB 980703 a precious sample in gamma-ray burst research. Here we use the observational data of GRB 980703 to test the standard fireball model in depth. It is found that the model can give a satisfactory explanation to the multi-band and overall afterglow light curves. The beaming angle of GRB 980703 is derived as ～ 0.23 radian, and the circum-burst medium density is ～ 27 cm?3. The total isotropic equivalent kinetic energy of the ejecta is ～ 3.8 × 1052 ergs. A rest-frame extinction of A V ～ 2.5 mag in the host galaxy is also derived.

关 键 词：gamma RAY BURSTS jets and OUTFLOWS AFTERGLOWS HYDRODYNAMICS shock waves 

分 类 号：P172.3[天文地球—天文学]