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GRB 221009A的射电至GeV余辉

The Radio to GeV Afterglow of GRB 221009A

Tanmoy Laskar, Kate D. Alexander, Raffaella Margutti, Tarraneh Eftekhari, Ryan Chornock, Edo Berger, Yvette Cendes, Anne Duerr, Daniel A. Perley, Maria Edvige R… 展开作者

Tanmoy Laskar, Kate D. Alexander, Raffaella Margutti, Tarraneh Eftekhari, Ryan Chornock, Edo Berger, Yvette Cendes, Anne Duerr, Daniel A. Perley, Maria Edvige Ravasio, Ryo Yamazaki, Eliot H. Ayache, Thomas Barclay, Rodolfo Barniol Duran, Shivani Bhandari, Daniel Brethauer, Collin T. Christy, Deanne L. Coppejans, Paul Duffell, Wen-fai Fong, Andreja Gomboc, Cristiano Guidorzi, Jamie A. Kennea, Shiho Kobayashi, Andrew Levan, Andrei P. Lobanov, Brian D. Metzger, Eduardo Ros, Genevieve Schroeder, P. K. G. Williams

AI总结:

本研究通过多波长观测分析GRB 221009A的余辉,发现其数据部分符合正向激波模型,但需额外发射成分,且该成分演化挑战现有余辉理论标准假设。

摘要:

GRB 221009A ($z=0.151$) 是已知最近的长期$γ$射线暴(GRBs)之一。其在所有电磁波长上的极端亮度为极其详细地研究这一仍然神秘的暂现源类别的一员提供了前所未有的机会。我们展示了这一非凡事件的多波长观测,跨越了从射电到$γ$射线的15个数量级的光子能量。我们发现,这些数据可以部分由来自高度准直的相对论性喷流与低密度类星风介质相互作用的正向激波(FS)来解释。在此模型下,喷流的束流修正动能($E_K \sim 4\times10^{50}$ erg)对于GRB群体来说是典型的。射电和毫米波数据对FS模型提供了强烈的限制约束,但需要存在一个额外的发射成分。根据能量均分论证,我们发现射电发射可能由少量质量($\lesssim6\times10^{-7} M_\odot$)以相对论性速度($\Gamma\gtrsim9$)运动并携带大动能($\gtrsim10^{49}$ erg)产生。然而,该成分的时间演化并不遵循来自单一幂律分布电子(例如在反向激波或双成分喷流中)的同步辐射或热电子群体的预期,这可能表明余辉理论中的某个标准假设被违反。GRB 221009A在未来几年内可能仍可被射电望远镜探测到,为追踪强大相对论性喷流的完整生命周期提供了宝贵机会。

英文摘要:

GRB 221009A ($z=0.151$) is one of the closest known long $γ$-ray bursts (GRBs). Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member of this still-mysterious class of transients in exquisite detail. We present multi-wavelength observations of this extraordinary event, spanning 15 orders of magnitude in photon energy from radio to $γ$-rays. We find that the data can be partially explained by a forward shock (FS) from a highly-collimated relativistic jet interacting with a low-density wind-like medium. Under this model, the jet's beaming-corrected kinetic energy ($E_K \sim 4\times10^{50}$ erg) is typical for the GRB population. The radio and mm data provide strong limiting constraints on the FS model, but require the presence of an additional emission component. From equipartition arguments, we find that the radio emission is likely produced by a small amount of mass ($\lesssim6\times10^{-7} M_\odot$) moving relativistically ($Γ\gtrsim9$) with a large kinetic energy ($\gtrsim10^{49}$ erg). However, the temporal evolution of this component does not follow prescriptions for synchrotron radiation from a single power-law distribution of electrons (e.g. in a reverse shock or two-component jet), or a thermal electron population, perhaps suggesting that one of the standard assumptions of afterglow theory is violated. GRB 221009A will likely remain detectable with radio telescopes for years to come, providing a valuable opportunity to track the full lifecycle of a powerful relativistic jet.

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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