We study the high-energy properties of GRB 181123B, a short gamma-ray burst (sGRB) at redshift z ≈ 1.75. We show that, despite its nominal short duration with T ₉₀ < 2 s, this burst displays evidence of a temporally extended emission (EE) at high energies and that the same trend is observed in the majority of sGRBs at z ≳ 1. We discuss the impact of instrumental selection effects on the GRB classification, stressing that the measured T ₉₀ is not an unambiguous indicator of the burst physical origin. By examining their environment (e.g., stellar mass, star formation, offset distribution), we find that these high-z sGRBs share many properties of long GRBs at a similar distance and are consistent with a short-lived progenitor system. If produced by compact binary mergers, these sGRBs with EE may be easier to localize at large distances and herald a larger population of sGRBs in the early universe.

我们研究了 GRB 181123B 的高能特性，这是一种红移z ≈ 1.75的短伽马射线暴 (sGRB) 。我们表明，尽管它的标称持续时间很短，T ₉₀ < 2 s，但这次爆发显示出高能量下时间延长发射 (EE) 的证据，并且在z ≳ 1处的大多数 sGRB 中观察到了相同的趋势。我们讨论仪器选择效应对 GRB 分类的影响，强调测得的T ₉₀并不是爆发物理起源的明确指标。通过检查它们的环境（例如，恒星质量、恒星形成、偏移分布），我们发现这些高zsGRB 具有相似距离的长 GRB 的许多特性，并且与短寿命的祖先系统一致。如果由紧凑的双星合并产生，这些带有 EE 的 sGRB 可能更容易在远距离定位，并预示着早期宇宙中 sGRB 的数量更大。