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GRB 120422A/SN 2012bz:连接低光度与高光度伽马射线暴的桥梁

高能天体物理现象 2014-07-02 v1 宇宙学与河外天体物理

摘要

在低红移处,已发现少量峰值光度(Liso<1048.5 ergs1L_{\rm iso} < 10^{48.5}~\rm{erg\,s}^{-1})远低于更遥远伽马射线暴(GRBs)平均值(Liso>1049.5 ergs1L_{\rm iso} > 10^{49.5}~\rm{erg\,s}^{-1})的伽马射线暴。若干低光度(low-LL)GRBs 的性质表明它们可能源于激波突破,而非超相对论性喷流的辐射。正因如此,这两类群体如何关联以及它们之间是否存在连续过渡备受争议。2012年4月22日探测到的红移 z=0.283z=0.283 爆发是迄今为止探测到的极少数中等光度 GRBs 之一,其伽马射线光度为 L1048.9 ergs1L\sim10^{48.9}~\rm{erg\,s}^{-1}。结合对其伴随超新星 SN 2012bz 的可靠探测,它有潜力回答关于低光度和高光度 GRBs 起源以及 GRB-SN 联系的重要问题。我们利用6--10米级望远镜的中低分辨率光谱仪开展了光谱观测活动,覆盖时间跨度为37.3天,并开展了从射电到X射线能段、持续约270天的多波段成像观测活动。此外,我们使用以 Hα\alpha 为中心的可调谐滤波器来绘制宿主星系及周围星系的恒星形成图。我们利用这些数据提取并建模了不同辐射组分的性质,并结合光谱能量分布拟合技术提取了宿主星系的性质。对从射电到X射线的光变曲线和光谱能量分布的建模表明,爆炸波以初始洛伦兹因子 Γ060\Gamma_0\sim60 膨胀(对于高光度 GRB 而言偏低),且余辉在亚毫米波段的峰值光度密度极低,为 2×1030 ergs1Hz1\lesssim2\times10^{30}~\rm{erg\,s}^{-1}\,\rm{Hz}^{-1}。[有删减]

关键词

引用

@article{arxiv.1401.3774,
  title  = {GRB 120422A/SN 2012bz: Bridging the Gap between Low- And High-Luminosity GRBs},
  author = {S. Schulze and D. Malesani and A. Cucchiara and N. R. Tanvir and T. Krühler and A. de Ugarte Postigo and G. Leloudas and J. Lyman and D. Bersier and K. Wiersema and D. A. Perley and P. Schady and J. Gorosabel and J. P. Anderson and A. J. Castro-Tirado and S. B. Cenko and A. De Cia and L. E. Ellerbroek and J. P. U. Fynbo and J. Greiner and J. Hjorth and D. A. Kann and L. Kaper and S. Klose and A. J. Levan and S. Martín and P. T. O'Brien and K. L. Page and G. Pignata and S. Rapaport and R. Sánchez-Ramírez and J. Sollerman and I. A. Smith and M. Sparre and C. C. Thöne and D. J. Watson and D. Xu and F. E. Bauer and M. Bayliss and G. Björnsson and M. Bremer and Z. Cano and S. Covino and V. D'Elia and D. A. Frail and S. Geier and P. Goldoni and O. E. Hartoog and P. Jakobsson and H. Korhonen and K. Y. Lee and B. Milvang-Jensen and M. Nardini and A. Nicuesa Guelbenzu and M. Oguri and S. B. Pandey and G. Petitpas and A. Rossi and A. Sandberg and S. Schmidl and G. Tagliaferri and R. P. J. Tilanus and J. M. Winters and D. Wright and E. Wuyts},
  journal= {arXiv preprint arXiv:1401.3774},
  year   = {2014}
}

备注

30 pages, 17 figures, 9 tables; abstract is abridged; images are shown at reduced resolution; comments are welcome