A binary black hole (BH) astrophysical scenario where a mass-constrained (2.5 × 10−13M⊙) primordial black hole (PBH) undergoes a radial fall on to its heavier component (such as a supermassive black hole, SMBH) is described as an intense gamma-ray emission event. As the relativistic PBH approaches the Schwarschild SMBH event horizon, its Lorentz-boosted Hawking radiation progressively reduces to a near-zero emission cone resulting in a highly collimated thermal beam. Accordingly, our numerically calculated PBH flux density Sν and νSν fluence spectrum show a decreasing Planck-like spectral dependence consistent with the cooling behaviour of thermal-dominant gamma-ray bursts (GRBs). Our results might provide an alternative explanation for thermal GRBs based on PBH origin.

中文翻译：

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热伽马射线爆发的原始黑洞起源

一个双黑洞 (BH) 天体物理场景，其中质量受限 (2.5 × 10−13M⊙) 的原始黑洞 (PBH) 径向坠落到其较重的组件（例如超大质量黑洞，SMBH）上，描述为强烈的伽马射线发射事件。随着相对论 PBH 接近 Schwarschild SMBH 事件视界，其洛伦兹增强的霍金辐射逐渐减少到接近零的发射锥，从而产生高度准直的热光束。因此，我们数值计算的 PBH 通量密度 Sν 和 νSν 通量谱显示出与热主导伽马射线暴 (GRB) 的冷却行为一致的类普朗克光谱依赖性降低。我们的结果可能为基于 PBH 起源的热 GRB 提供了另一种解释。