We report our study of the field of the ≃0.2 PeV neutrino event IC-190619A. This neutrino belongs to Gold events, which more likely have an astrophysical origin. Among the two γ-ray sources within the neutrino’s positional uncertainty region, we find that one of them, the BL Lac–type blazar PKS 2254+074, had a γ-ray flare at the arrival time of the neutrino. The flare is determined to have lasted ∼2.5 yr in a 180 day binned light curve, constructed from the data collected with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Accompanying the flare, optical and mid-infrared brightening is also seen. In addition, ≥10 GeV high-energy photons from the source have been detected, suggesting a hardening of the emission during the flare. Given both the positional and temporal coincidence of PKS 2254+074 with IC-190619A, we suggest that this blazar is likely another member of a few recently identified (candidate) neutrino-emitting blazars.

中文翻译：

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PKS 2254+074：可能与中微子事件 IceCube-190619A 有关的 Blazar


我们报告了我们对 ≃0.2 PeV 中微子事件 IC-190619A 领域的研究。这个中微子属于黄金事件，它更有可能起源于天体物理学。在中微子位置不确定性区域内的两个γ射线源中，我们发现其中一个，BL Lac 型 blazar PKS 2254+074，在中微子到达时发生了γ射线耀斑。在 2.5 天的分档光曲线中，确定耀斑持续了 180 年，该曲线是根据费米伽马射线太空望远镜上的大面积望远镜收集的数据构建的。伴随着耀斑，还可以看到光学和中红外增亮。此外，已经检测到来自源的 ≥10 GeV 高能光子，这表明耀斑期间的发射变硬。鉴于 PKS 2254+074 与 IC-190619A 的位置和时间重合，我们认为这个 blazar 可能是最近确定的几个（候选）中微子发射 blazar 的另一个成员。