Ten per cent polarized optical emission from GRB 090102

Article

关键词: GAMMA-RAY BURSTS;    SPACE-TELESCOPE;    AFTERGLOWS;    GRB-021206;    FIREBALL;    MODEL;    SHOCK;   

DOI  :  10.1038/nature08590

来源: SCIE

【 摘 要 】

The nature of the jets and the role of magnetic fields in gamma-ray bursts (GRBs) remains unclear(1,2). In a baryon-dominated jet only weak, tangled fields generated in situ through shocks would be present(3). In an alternative model, jets are threaded with large-scale magnetic fields that originate at the central engine and that accelerate and collimate the material(4). To distinguish between the models the degree of polarization in early-time emission must be measured; however, previous claims of gamma-ray polarization have been controversial(5-8). Here we report that the early optical emission from GRB 090102 was polarized at 10 +/- 1 per cent, indicating the presence of large-scale fields originating in the expanding fireball. If the degree of polarization and its position angle were variable on timescales shorter than our 60-second exposure, then the peak polarization may have been larger than ten per cent.

【 授权许可】

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