伽马暴GRB 221009A的观测角限制  

The Viewing Angle Limitation of GRB 221009A

作　　者：林一清[1,2] LIN Yiqing(Fujian Provincial Key Laboratory of Optoelectronic Technology and Devices,Xiamen University of Technology,Xiamen 361024,China;School of Opto-electronic and Communication Engineering,Xiamen University of Technology,Xiamen 361024,China)

机构地区：[1]厦门理工学院福建省光电技术与器件重点实验室,厦门361024 [2]厦门理工学院光电与通信工程学院,厦门361024

出　　处：《天文学进展》2024年第4期650-655,共6页Progress In Astronomy

基　　金：福建自然科学基金(2021J011215);厦门市青年创新项目(3502Z20206077);厦门理工学院校级教研教改项目(JG2022-0123846)。

摘　　要：GRB 221009A被称为“史上最亮”(BOAT)的伽马射线暴,在所有波长下被许多卫星探测到。它是迄今为止观测到的具有最高各向同性能(E_(iso)≈1.5×10^(48)J)、离地球较近(红移为z=0.151)的伽马射线暴。伽马暴的辐射起源于相对论喷流,它们的各项同性能可能取决于喷流的内禀能量、喷流的张角和相对喷流的观测角。根据长暴的E_(p,i)-E_(iso)关系和Γ-E_(iso)关系,估算了GRB 221009A的观测视线与喷流边缘的夹角θ′_(obs)和洛伦兹因子Γ,结果为Γ=(4.23±2.81)×10^(3),观测角θ′_(obs)=(0.03±0.01)°。这个结果表明,对于GRB 221009A,观测视线与喷流边缘的夹角非常小,即GRB 221009A是正轴观测,这可能是GRB 221009A具有最高各向同性能的原因之一。Long gamma-ray burst(GRB)GRB 221009A,known as the\rightest-of-all-time"(BOAT),triggered all satellites equipped for transient detection in all wavelengths.Relative to other GRBs ever detected by the humanity in the past half century,the uence and peak ux of GRB 221009A are the highest.At a redshift of z=0:151,GRB 221009A holds the record of the highest ever measured isotropic energy E_(iso).Prompt gamma-ray emission is thought to be the result of a highly relativistic and collimated jet with a small inclination angle with respect to the Earth.Thus,the measured isotropic energy may depends on the intrinsic energy of the jet,the opening angle of the jet,and the viewing angle of the relative jet.Here we use the relations E_(p,i)-E_(iso) and-E_(iso) of the long burst to determine the viewing angleθ′_(obs) and the Lorentz factorof long GRB 221009。Our results show=(4:23±2:81)×10^(3) andθ′_(obs)=0:03°±0:01°for long GRB 221009A.The result indicates that for GRB 221009A,the viewing angle between the line of sight and the jet edge of GRB 221009A is very small.That is,GRB 221009A may be a positive axis _(obs)ervation,which may be one of the reasons that GRB 221009A has the highest E_(iso).

关 键 词：伽马射线暴 喷流 相对论过程 

分 类 号：P172.3[天文地球—天文学]