标题： 伽马射线暴221009A真的是一次一万个年一遇的事件吗？ 显示英文标题

标题： Is Gamma-ray Burst 221009A Really a Once-in-10,000 Year Event?

摘要： 伽马射线暴（GRBs）比已观测到最明亮的GRB 221009A更明亮的，之前估计其发生率为每10,000年一次，这是基于对长时GRB群体通量分布的外推。 我们表明，如果这些爆发来自一个单独的窄喷流GRB群体，它们的发生率可能高达每200年一次。 为了避免过度产生较暗GRBs的观测率，这个群体必须具有大约$z\approx 0.38$的最大红移。 我们表明，需要$> 100$年时间才能通过使用$\gamma$射线探测器观察到另一个来自该群体的GRB来确认这个新群体；通过Vera Rubin天文台观察来自该群体的孤儿光学余辉，或通过平方公里阵列望远镜观察来自该群体的孤儿射电余辉，也需要同样长的时间来观察，而且尚不清楚它们是否能与标准GRB群体区分开来。 我们表明，附近的窄喷流群体在产生超高能宇宙射线方面具有更有利的能量特性，比标准GRB更优。 来自窄喷流群体、亮度足以导致地球生命大规模灭绝的银河系内爆发的发生率估计约为每5亿年一次。 这个GRB群体可能会使银河系内的生命更难出现，这对未来在系外行星上寻找生命有影响。 显示英文摘要

摘要： Gamma-ray bursts (GRBs) brighter than the GRB 221009A, the brightest yet observed, have previously been estimated to occur at a rate of 1 per 10,000 years, based on the extrapolation of the distribution of fluences of the Long GRB population. We show that bursts this bright could instead have a rate as high as approximately one per 200 years if they are from a separate population of narrow-jet GRBs. This population must have a maximum redshift of about $z\approx 0.38$ in order to avoid over-producing the observed rate of fainter GRBs. We show that it will take $> 100$ years to confirm this new population based on observing another GRB from it with a $\gamma$-ray detector; observing an orphan optical afterglow from this population with Vera Rubin Observatory or an orphan radio afterglow with the Square Kilometer Array will also take similarly long times to observe, and it is unclear if they could be distinguished from the standard GRB population. We show that the nearby narrow-jet population has more favorable energetics for producing ultra-high energy cosmic rays than standard GRBs. The rate of bursts in the Milky Way bright enough to cause mass extinctions of life on Earth from the narrow jet population is estimated to be approximately 1 per 500 Myr. This GRB population could make life in the Milky Way less likely, with implications for future searches for life on exoplanets.