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arXiv 1401.5565astro-ph.HEastro-ph.CO
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宇宙中的第一次伽马射线暴

The First Gamma-Ray Bursts in the Universe

R. A. Mesler, Daniel J. Whalen, Joseph Smidt, Chris L. Fryer, N. M. Lloyd-Ronning, Y. M. Pihlström

摘要:

伽马射线暴(GRB)是终极的宇宙灯塔,能够照亮宇宙的最早时期。这样的事件能探测到z $\sim$ 20(宇宙黑暗时代的结束)的第一批恒星的性质吗?以前对第三星族伽玛暴的研究只考虑了它们祖先的扩散遗迹H II区域的爆炸,或者比迄今为止观察到的爆炸更有活力的爆炸。但是,产生最高红移的伽马射线暴的过程可能会重置它们的局部环境,创造出比迄今为止相对论喷流模型更为复杂的结构。这些结构可以极大地影响余辉的亮度,因此可以检测到它的红移。我们现在已经模拟了星族III GRB在H II区域的余辉,风,以及恒星在产生爆发的过程中喷出的致密壳层。我们的模型,这已被用于在以前的工作中,已被扩展到包括反向冲击,逆康普顿冷却和冲击波中的球形度和光束的影响的贡献,并在各种回旋射流密度分布是有效的。我们发现E $_{\mathrm{iso},γ} =$ 10 $^{ 51}$ - 10 $^{53}$ erg的伽玛暴将在z $\gtrsim$ 20处对下一代近红外和射电天文台可见。在许多情况下,可以从余辉光曲线推断爆发的环境,从而推断出祖先的类型。虽然Swift和甚大阵列现在可以看到一些第三星族GRB,但探测它们的最佳策略将是未来的任务,如EXIST和JANUS,它们具有大的调查区域和机载X射线和红外望远镜,可以从爆发的那一刻起跟踪它们的近红外通量,从而确定其红移。

英文摘要:

Gamma-ray bursts (GRBs) are the ultimate cosmic lighthouses, capable of illuminating the universe at its earliest epochs. Could such events probe the properties of the first stars at z $\sim$ 20, the end of the cosmic Dark Ages? Previous studies of Population III GRBs only considered explosions in the diffuse relic H II regions of their progenitors, or bursts that are far more more energetic than those observed to date. But the processes that produce GRBs at the highest redshifts likely reset their local environments, creating much more complicated structures than those in which relativistic jets have been modeled so far. These structures can greatly affect the luminosity of the afterglow, and hence the redshift at which it can be detected. We have now simulated Population III GRB afterglows in H II regions, winds, and dense shells ejected by the star during the processes that produce the burst. Our model, which has been used in previous work, has been extended to include contributions from reverse shocks, inverse Compton cooling and the effects of sphericity and beaming in the blast wave, and is valid in a variety of circumjet density profiles. We find that GRBs with E$_{\mathrm{iso},γ} =$ 10$^{ 51}$ - 10$^{53}$ erg will be visible at z $\gtrsim$ 20 to the next generation of near infrared and radio observatories. In many cases, the environment of the burst, and hence progenitor type, can be inferred from the afterglow light curve. Although some Population III GRBs are visible to Swift and the Very Large Array now, the optimal strategy for their detection will be future missions like EXIST and JANUS, which have large survey areas and onboard X-ray and infrared telescopes that can track their near infrared flux from the moment of the burst, thereby identifying its redshift.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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