论文标题
GRB 210204a的长期活跃余辉：检测伽马射线中最延迟的耀斑
The long-active afterglow of GRB 210204A: Detection of the most delayed flares in a Gamma-Ray Burst
论文作者
论文摘要
我们在30天内对GRB 210204A的广泛宽带随访提出了结果。我们在突发后的7.6 x 10^5 s和1.1 x 10^6 s的余辉中检测到光耀斑：在GRB余辉中检测到的最延迟的耀斑。在0.876的源红移时，其剩余延迟为5.8 x 10^5 s（6.71 d）。我们调查了这种燃烧的可能原因，并得出结论，最有可能的原因是喷气机中的刷新冲击。 GRB的及时发射在典型的长突发范围内：它显示了三个不结合发射发作，所有发射都遵循典型的GRB相关性。这表明GRB 210204A可能没有任何引起迟发时间的特殊特性，并且由于迟到的观察很少而导致了其他次要的这种检测。较大的GRB样本的系统性后续随访可以使这种余辉行为更加阐明。对GRB 210204a的进一步分析表明，由于红移（z）= 0.876处的sne，光曲线中的较晚时间颠簸极不可能，并且更有可能是由于较晚的时间膨胀活动。由于恶劣的天气条件在很晚时限制了多波段数据，因此这种变异性的原因无法明确量化。 GRB 210204a的耀斑是迄今为止发现的最新耀斑。
We present results from extensive broadband follow-up of GRB 210204A over the period of thirty days. We detect optical flares in the afterglow at 7.6 x 10^5 s and 1.1 x 10^6 s after the burst: the most delayed flaring ever detected in a GRB afterglow. At the source redshift of 0.876, the rest-frame delay is 5.8 x 10^5 s (6.71 d). We investigate possible causes for this flaring and conclude that the most likely cause is a refreshed shock in the jet. The prompt emission of the GRB is within the range of typical long bursts: it shows three disjoint emission episodes, which all follow the typical GRB correlations. This suggests that GRB 210204A might not have any special properties that caused late-time flaring, and the lack of such detections for other afterglows might be resulting from the paucity of late-time observations. Systematic late-time follow-up of a larger sample of GRBs can shed more light on such afterglow behaviour. Further analysis of the GRB 210204A shows that the late time bump in the light curve is highly unlikely due to underlying SNe at redshift (z) = 0.876 and is more likely due to the late time flaring activity. The cause of this variability is not clearly quantifiable due to the lack of multi-band data at late time constraints by the bad weather conditions. The flare of GRB 210204A is the latest flare detected to date.
