Self-organized criticality in multi-pulse gamma-ray bursts

• 作者: Fen Lyu Ya-Ping Li Shu-Jin Hou Jun-Jie Wei Jin-Jun Geng Xue-Feng Wu
• 来源期刊: 物理学前沿
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: Particle,Nuclear Physics,Astrophysics & Cosmology
• 页码范围: 84-91
• 页数: 8页
• 语种: 英文

摘要

The variability in multi-pulse gamma-ray bursts (GRBs) may help to reveal the mechanism of underlying processes from the central engine.To investigate whether the self-organized criticality (SOC) phenomena exist in the prompt phase of GRBs,we statistically study the properties of GRBs with more than 3 pulses in each burst by fitting the distributions of several observed physical variables with a Markov Chain Monte Carlo approach,including the isotropic energy Eiso,the duration time T,and the peak count rate P of each pulse.Our sample consists of 454 pulses in 93 GRBs observed by the CGRO/BATSE satellite.The best-fitting values and uncertainties for these power-law indices of the differential frequency distributions are: αdE=1.54±0.09,αdT=1.82+0.14-0.15 and αdP =2.09+0.18-0.19,while the power-law indices in the cumulative frequency distributions are: αcE=1.44+0.08-0.10,αcT=1.75+0.11-0.13 and αcP =1.99+0.16-0.19,We find that these distributions are roughly consistent with the physical framework of a Fractal-Diffusive,Self-Organized Criticality (FD-SOC) system with the spatial dimension S =3 and the classical diffusionβ=1.Our results support that the jet responsible for the GRBs should be magnetically dominated and magnetic instabilities (e.g.,kink model,or tearing-model instability) lead the GRB emission region into the SOC state.