Probing the Nature of the Weakest Intergalactic Magnetic Fields with the High-Energy Emission of Gamma-Ray Bursts
Probing the Nature of the Weakest Intergalactic Magnetic Fields with the High-Energy Emission of Gamma-Ray Bursts
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DOI：
10.1086/588275
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发表时间：
2007-11
期刊：
影响因子：
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通讯作者：
K. Ichiki;S. Inoue;Keitaro Takahashi
中科院分区：
文献类型：
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作者：
K. Ichiki;S. Inoue;Keitaro Takahashi
我们研究伽马射线暴的延迟二次 GeV-TeV 发射及其探测星系间磁场性质的潜力。对于来自电子-正电子对的初级高能光子和次级逆康普顿光子之间的时间延迟，适当考虑了几何效应，这些电子-正电子对是在与背景辐射场的 γ-γ 相互作用中产生的，并通过干扰磁场偏转。针对各种磁场强度和红移来评估延迟发射的时间相关光谱。如果场强约为 10−18 G，则 z ∼ 1 处爆发的次级光子的典型通量和延迟时间分别为约 10−8 GeV cm−2 s−1 和约 104 s，就像星系间空隙区域的情况一样。我们发现相干磁场和纠缠磁场的情况之间存在重要差异，以及对场相干长度的依赖性。
We investigate the delayed, secondary GeV-TeV emission of gamma-ray bursts and its potential to probe the nature of intergalactic magnetic fields. Geometrical effects are properly taken into account for the time delay between primary high-energy photons and secondary inverse Compton photons from electron-positron pairs, which are produced in γ-γ interactions with background radiation fields and deflected by intervening magnetic fields. The time-dependent spectra of the delayed emission are evaluated for a wide range of magnetic field strengths and redshifts. The typical flux and delay time of secondary photons from bursts at z ∼ 1 are, respectively, ~10−8 GeV cm−2 s−1 and ~104 s if the field strengths are ~10−18 G, as might be the case in intergalactic void regions. We find crucial differences between the cases of coherent and tangled magnetic fields, as well as dependences on the field coherence length.