Fast radio bursts (FRBs) are a powerful and mysterious new class of transients that are luminous enough to be detected at cosmological distances. By associating FRBs to host galaxies, we can measure intrinsic and environmental properties that test FRB origin models, in addition to using them as precise probes of distant cosmic gas. The Deep Synoptic Array (DSA-110) is a radio interferometer built to maximize the rate at which it can simultaneously detect and localize FRBs. Here, we present the first sample of FRBs and host galaxies discovered by the DSA-110. This sample of 11 FRBs is the largest, most uniform sample of localized FRBs to date, as it is selected based on association with host galaxies identified in optical imaging by Pan-STARRS1. These FRBs have not been observed to repeat, and their radio properties (dispersion, temporal scattering, energy) are similar to that of the known nonrepeating FRB population. Most host galaxies have ongoing star formation, as has been identified before for FRB hosts. Two hosts of the new sample are massive, quiescent galaxies. The distribution of star formation history across this host-galaxy sample shows that the delay time distribution is wide, with a power-law model that spans from ∼100 Myr to ≳2 Gyr. This requires the existence of one or more progenitor formation channels associated with old stellar populations, such as the binary evolution of compact objects.

中文翻译：

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深层天气阵列科学：第一个 FRB 和宿主星系目录


快速射电爆发（FRB）是一种强大而神秘的新型瞬变，其亮度足以在宇宙距离上被检测到。通过将快速射电暴与宿主星系联系起来，除了将它们用作遥远宇宙气体的精确探测器之外，我们还可以测量测试快速射电暴起源模型的内在和环境特性。深度天气阵列 (DSA-110) 是一款无线电干涉仪，旨在最大限度地提高同时检测和定位 FRB 的速率。在这里，我们展示了 DSA-110 发现的第一个 FRB 和宿主星系样本。这 11 个 FRB 样本是迄今为止最大、最均匀的局域 FRB 样本，因为它是根据 Pan-STARRS1 光学成像中识别的宿主星系的关联而选择的。这些快速射电暴尚未被观察到重复，它们的射电特性（色散、时间散射、能量）与已知的非重复快速射电暴群相似。大多数宿主星系都有持续的恒星形成，正如之前针对快速射电暴宿主所发现的那样。新样本的两个宿主是巨大的静止星系。该宿主星系样本中恒星形成历史的分布表明，延迟时间分布很宽，幂律模型的跨度从 ∼100 Myr 到 ≳2 Gyr。这需要存在一个或多个与古老恒星群体相关的祖细胞形成通道，例如致密天体的二元演化。