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GRB 120422 A/ SN 2012 bz:弥合低亮度和高亮度伽玛暴之间的差距

GRB 120422A/SN 2012bz: Bridging the Gap between Low- And High-Luminosity GRBs

S. Schulze, D. Malesani, A. Cucchiara, N. R. Tanvir, T. Krühler, A. de Ugarte Postigo, G. Leloudas, J. Lyman, D. Bersier, K. Wiersema, D. A. Perley, P. Schady, … 展开作者

S. Schulze, D. Malesani, A. Cucchiara, N. R. Tanvir, T. Krühler, A. de Ugarte Postigo, G. Leloudas, J. Lyman, D. Bersier, K. Wiersema, D. A. Perley, P. Schady, J. Gorosabel, J. P. Anderson, A. J. Castro-Tirado, S. B. Cenko, A. De Cia, L. E. Ellerbroek, J. P. U. Fynbo, J. Greiner, J. Hjorth, D. A. Kann, L. Kaper, S. Klose, A. J. Levan, S. Martín, P. T. O'Brien, K. L. Page, G. Pignata, S. Rapaport, R. Sánchez-Ramírez, J. Sollerman, I. A. Smith, M. Sparre, C. C. Thöne, D. J. Watson, D. Xu, F. E. Bauer, M. Bayliss, G. Björnsson, M. Bremer, Z. Cano, S. Covino, V. D'Elia, D. A. Frail, S. Geier, P. Goldoni, O. E. Hartoog, P. Jakobsson, H. Korhonen, K. Y. Lee, B. Milvang-Jensen, M. Nardini, A. Nicuesa Guelbenzu, M. Oguri, S. B. Pandey, G. Petitpas, A. Rossi, A. Sandberg, S. Schmidl, G. Tagliaferri, R. P. J. Tilanus, J. M. Winters, D. Wright, E. Wuyts

摘要:

在低红移时,少数伽马射线暴(GRB)的峰值亮度($L_{\rm iso} < 10^{48.5}~\rm{erg\,s}^{-1}$)大大低于更远的平均值($L_{\rm iso} > 10^{49.5}~\rm{erg\,s}^{-1}$)。几个低光度(低- $L$)伽玛暴的性质表明,它们可能是由于冲击爆发,而不是从超相对论喷流的发射。因此,人们对这两个群体是如何联系在一起的,以及它们之间是否存在连续性进行了激烈的辩论。2012年4月22日的$z=0.283$红移爆发是迄今为止探测到的极少数$γ$射线光度为$L\sim10^{48.9}~\rm{erg\,s}^{-1}$的中间$L$伽马暴之一。再加上对其伴随的超新星SN 2012 bz的强大探测,它有可能回答关于低和高$L$ GRB起源以及GRB与SN联系的重要问题。我们在6- 10米级望远镜上使用中分辨率和低分辨率摄谱仪进行了一次光谱学活动,覆盖时间跨度为37.3天,并在$\sim270$天内进行了从无线电到X射线能量的多波长成像活动。此外,我们使用了一个可调的过滤器为中心的H $α$映射恒星形成的主星系和周围的星系。我们使用这些数据来提取和模拟不同辐射成分的特性,并结合光谱能量分布拟合技术来提取宿主星系的特性。对从射电到X射线的光变曲线和光谱能量分布的模拟显示,爆炸波以初始洛伦兹因子$Γ_0\sim60$膨胀,对于高$L$伽马射线暴来说很低,并且余辉具有异常低的峰值亮度密度$\lesssim2\times10^{30}~\rm{erg\,s}^{-1}\,\rm{Hz}^{-1}$,在亚毫米级。[摘要]

英文摘要:

At low redshift, a handful of gamma-ray bursts (GRBs) have been discovered with peak luminosities ($L_{\rm iso} < 10^{48.5}~\rm{erg\,s}^{-1}$) substantially lower than the average of the more distant ones ($L_{\rm iso} > 10^{49.5}~\rm{erg\,s}^{-1}$). The properties of several low-luminosity (low-$L$) GRBs indicate that they can be due to shock break-out, as opposed to the emission from ultrarelativistic jets. Owing to this, it is highly debated how both populations are connected, and whether there is a continuum between them. The burst at redshift $z=0.283$ from 2012 April 22 is one of the very few examples of intermediate-$L$ GRBs with a $γ$-ray luminosity of $L\sim10^{48.9}~\rm{erg\,s}^{-1}$ that have been detected up to now. Together with the robust detection of its accompanying supernova SN 2012bz, it has the potential to answer important questions on the origin of low- and high-$L$ GRBs and the GRB-SN connection. We carried out a spectroscopy campaign using medium- and low-resolution spectrographs at 6--10-m class telescopes, covering the time span of 37.3 days, and a multi-wavelength imaging campaign from radio to X-ray energies over a duration of $\sim270$ days. Furthermore, we used a tuneable filter centred at H$α$ to map star formation in the host galaxy and the surrounding galaxies. We used these data to extract and model the properties of different radiation components and incorporate spectral-energy-distribution fitting techniques to extract the properties of the host galaxy. Modelling the light curve and spectral energy distribution from the radio to the X-rays revealed the blast-wave to expand with an initial Lorentz factor of $Γ_0\sim60$, low for a high-$L$ GRB, and that the afterglow had an exceptional low peak luminosity-density of $\lesssim2\times10^{30}~\rm{erg\,s}^{-1}\,\rm{Hz}^{-1}$ in the sub-mm. [Abridged]

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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