Investigating the nature of the INTEGRAL gamma-ray bursts and sub-threshold triggers with Swift follow-up
Investigating the nature of the INTEGRAL gamma-ray bursts and sub-threshold triggers with Swift follow-up
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DOI：
10.1093/mnras/stx1163
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发表时间：
2017-05
影响因子：
4.8
通讯作者：
A. Higgins;R. Starling;D. Gotz;S. Mereghetti;K. Wiersema;T. Maccarone;J. Osborne;N. Tanvir;P. O’Brien;A. Bird;A. Rowlinson;N. Gehrels
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文献类型：
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作者：
A. Higgins;R. Starling;D. Gotz;S. Mereghetti;K. Wiersema;T. Maccarone;J. Osborne;N. Tanvir;P. O’Brien;A. Bird;A. Rowlinson;N. Gehrels
我们探索国际伽马射线天体物理实验室 (INTEGRAL) 的潜力，以提高我们对伽马射线暴 (GRB) 等爆炸性瞬变低能量流状态的理解。当伽马射线仪器记录到低于通常的强显着性阈值的强度峰值时，我们探讨了所谓的“弱”积分触发的本质。在有针对性的 Swift 后续活动中，我们观察到 15 个弱触发器。我们发现其中六个可以归类为伽玛暴。其中包括 GRB 150305A，这是我们仅从我们的活动中发现的 GRB。我们还确定了一个与触发因素 IGRW 151019 一致的源，作为候选活动星系核。我们表明，诸如伽玛暴之类的真实事件存在于整体突发警报系统（IBAS）弱触发群体中。完整 INTEGRAL IBAS 和 Swift-BAT GRB 样本的注量分布的比较表明两者相似。我们还发现了两个样本的瞬发伽马射线和 X 射线特性之间的相关性，支持了之前的研究。我们发现两颗卫星经常达到相似的低能量密度水平，尽管雨燕对短的、低能量密度的伽玛暴更敏感。
We explore the potential of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) to improve our understanding of the low-fluence regime for explosive transients, such as Gamma-ray Bursts (GRBs). We probe the nature of the so-called 'WEAK' INTEGRAL triggers, when the gamma-ray instruments record intensity spikes that are below the usual STRONG significance thresholds. In a targeted Swift follow-up campaign, we observed 15 WEAK triggers. We find six of these can be classified as GRBs. This includes GRB 150305A, a GRB discovered from our campaign alone. We also identified a source coincident with one trigger, IGRW 151019, as a candidate active galactic nucleus. We show that real events such as GRBs exist within the INTEGRAL Burst Alert System (IBAS) WEAK trigger population. A comparison of the fluence distributions of the full INTEGRAL IBAS and Swift-BAT GRB samples showed that the two are similar. We also find correlations between the prompt gamma-ray and X-ray properties of the two samples, supporting previous investigations. We find that both satellites reach similar, low fluence levels regularly, although Swift is more sensitive to short, low-fluence GRBs.