Variabilities of gamma-ray burst afterglows: Long-acting engine, anisotropic jet, or many fluctuating regions?

被引：161

作者：

Ioka, K ^{[1
]}

Kobayashi, S

Zhang, B

机构：

[1] Penn State Univ, Dept Phys, University Pk, PA 16802 USA

[2] Penn State Univ, Ctr Gravitat Wave Phys, Davey Lab 104, University Pk, PA 16802 USA

[3] Penn State Univ, Davey Lab 525, Dept Astron & Astrophys, University Pk, PA 16802 USA

[4] Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA

来源：

ASTROPHYSICAL JOURNAL | 2005年 / 631卷 / 01期

关键词：

gamma rays : bursts; gamma rays : theory; relativity;

D O I：

10.1086/432567

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We show that simple kinematic arguments can give limits on the timescale and amplitude of variabilities in gamma-ray burst (GRB) afterglows, especially when the variability timescale is shorter than the observed time since the burst, Delta t < t. These limits help us to identify the sources of afterglow variability. The afterglows of GRB 011211 and GRB 021004 marginally violate these limits. If such violation is confirmed by the Swift satellite, a possible explanation is that (1) the compact objects that power GRB jets continue to eject an intermittent outflow for a very long timescale (>= 1 day), (2) the GRB jet from the central engine has a temporal anisotropy with a large brightness contrast >= 10 and small angular structure >= 10(-2), or (3) many (>= 10(3)) regions fluctuate simultaneously in the emitting site.

引用

页码：429 / 434

页数：6

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