GRB 171205A/SN 2017iuk: A local low-luminosity gamma-ray burst
GRB 171205A/SN 2017iuk: A local low-luminosity gamma-ray burst
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DOI：
10.1051/0004-6361/201833847
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发表时间：
2018-10
影响因子：
6.5
通讯作者：
V. D’Elia;S. Campana;A. D’Aì;M. D. Pasquale;S. Emery;D. Frederiks;A. Lien;A. Melandri;K. Page;R. Starling;D. Burrows;A. Breeveld;S. Oates;P. O’Brien;J. Osborne;M. Siegel;G. Tagliaferri;P. Brown;S. Cenko;D. Svinkin;A. Tohuvavohu;A. Tsvetkova
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作者：
V. D’Elia;S. Campana;A. D’Aì;M. D. Pasquale;S. Emery;D. Frederiks;A. Lien;A. Melandri;K. Page;R. Starling;D. Burrows;A. Breeveld;S. Oates;P. O’Brien;J. Osborne;M. Siegel;G. Tagliaferri;P. Brown;S. Cenko;D. Svinkin;A. Tohuvavohu;A. Tsvetkova
上下文发生在本地宇宙的伽玛射线暴（GRB）是GRB家族中一个有趣的子类，因为它们的光度平均低于它们的宇宙学类似物。试图以全局的方式来理解这种特殊的行为仍然是不可能的，因为低红移伽玛暴的样本很小，并且单个物体的性质彼此差异太大。此外，它们的接近性（以及由此产生的高通量）使这些源成为理想的目标，即使用小型望远镜也可以进行广泛的跟踪，还考虑到这些伽马射线暴与超新星（SN）爆炸有着决定性的联系。目标。我们的目的是通过报告GRB 171205 A的情况下，有助于研究的局部爆发。这个源是由雨燕爆发警报望远镜（BAT）在2017年12月5日发现的，很快就与一个低红移的宿主星系（z = 0.037）和一个新兴的SN（SN 2017 iuk）相关联。方法.我们分析了完整的Swift数据集，包括紫外光学望远镜（UVOT），X射线望远镜（XRT）和BAT数据。此外，我们采用Konus-Wind高能数据作为γ射线能量的有价值的扩展。结果测光SN特征在UVOT u、B和ν滤波器中清晰可见。最大发射量在2013（静止帧）天达到，整个撞击与SN 2006 aj相似，但震级较低，时间偏移+2 d。在ν波段的预凸也清晰可见，这是第一次在GRB-SNe中没有观察到这种特征。它的物理起源不容易解释。X射线谱显示出氢柱密度NH，int = 7.4+4.1−3.6 × 1020 cm−2，即使只考虑低红移的伽玛暴，它也处于NH，int的低端。光谱还具有热分量，这在与SNe相关的伽玛暴中很常见，但其起源仍然是一个争论的问题。最后，γ射线带的各向同性能量Eiso = 2.18+0.63−5.0 × 1049 erg，低于宇宙学伽玛暴的能量。将这个值与同一带的峰值能量Ep = 125+141−37 keV相结合，意味着GRB 171205 A是阿马蒂关系的一个异常值，就像其他一些低红移的GRB一样，它的发射机制应该与更远的正则GRB不同。
Context. Gamma-ray bursts (GRBs) occurring in the local Universe constitute an interesting sub-class of the GRB family, since their luminosity is on average lower than that of their cosmological analogs. Attempts to understand in a global way this peculiar behaviour is still not possible, since the sample of low redshift GRBs is small, and the properties of individual objects are too different from each other. In addition, their closeness (and consequently high fluxes) make these sources ideal targets for extensive follow-up even with small telescopes, considering also that these GRBs are conclusively associated with supernova (SN) explosions. Aims. We aim to contribute to the study of local bursts by reporting the case of GRB 171205A. This source was discovered by Swift Burst Alert Telescope (BAT) on 2017, December 5 and soon associated with a low redshift host galaxy (z = 0.037), and an emerging SN (SN 2017iuk). Methods. We analyzed the full Swift dataset, comprising the UV-Optical Telescope (UVOT), X-ray Telescope (XRT) and BAT data. In addition, we employed the Konus-Wind high energy data as a valuable extension at γ-ray energies. Results. The photometric SN signature is clearly visible in the UVOT u, b and ν filters. The maximum emission is reached at ∼13 (rest frame) days, and the whole bump resembles that of SN 2006aj, but lower in magnitude and with a shift in time of +2 d. A prebump in the ν-band is also clearly visible, and this is the first time that such a feature is not observed achromatically in GRB–SNe. Its physical origin cannot be easily explained. The X-ray spectrum shows an intrinsic Hydrogen column density NH,int = 7.4+4.1−3.6 × 1020 cm−2, which is at the low end of the N H, int, even considering just low redshift GRBs. The spectrum also features a thermal component, which is quite common in GRBs associated with SNe, but whose origin is still a matter of debate. Finally, the isotropic energy in the γ-ray band, Eiso = 2.18+0.63−5.0 × 1049 erg, is lower than those of cosmological GRBs. Combining this value with the peak energy in the same band, Ep = 125+141−37 keV, implies that GRB 171205A is an outlier of the Amati relation, as are some other low redshift GRBs, and its emission mechanism should be different from that of canonical, farther away GRBs.