Abstract

A detailed analysis of the GBM/Fermi experiment data is carried out to classify GRB 200415A. It is shown that, on the one hand, this event exhibits typical for type I (short) gamma-ray bursts (GRBs) properties, such as duration, variability, and the character of spectral evolution (lag). On the other hand, the localization of the event source on the celestial plane, obtained by the triangulation method (IPN), indicates the nearby (\(D_{L}=3.5\) Mpc) galaxy NGC 253 (Sculptor) as a possible host galaxy for this burst. It introduces significant restrictions on the energetics of the event (\(E_{iso}\sim 10^{46}\) erg) and gives an alternative interpretation of GRB 200415A as a giant flare (GF) of a soft gamma repeater (SGR). This interpretation is supported by the atypically hard energy spectrum. In addition, according to the position of the burst on the \(E_{p,i}{-}E_{iso}\) (the position of the maximum in the energy spectrum \(\nu F_{\nu}\) in the source frame depending on the isotropic equivalent of the total energy, emitted in gamma rays) and \(T_{90,i}{-}EH\) (duration in the source frame depending on the combination of parameters \(EH=E_{p,i,2}E_{iso,51}^{-0.4}\)) diagrams, GRB 200415A is unambiguously classified as a giant flare of a magnetar, assuming its association with the galaxy NGC 253. In these diagrams, known giant flares in the Galaxy and candidates for giant flares in nearby galaxies form a well-defined group, which includes the GRB 200415A.

中文翻译：

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GRB 200415A：磁星大耀斑或短伽玛射线爆发？

摘要

对GBM / Fermi实验数据进行了详细分析，以对GRB 200415A进行分类。一方面表明，该事件表现出典型的I型（短）伽马射线暴（GRB）特性，例如持续时间，可变性和光谱演化特征（滞后）。另一方面，通过三角剖分法（IPN）获得的事件源在天体上的定位可能表明附近（\（D_ {L} = 3.5 \） Mpc）星系NGC 253（Sculptor）爆发的宿主银河系。它对事件的能量学（\（E_ {iso} \ sim 10 ^ {46} \）erg），并给出了GRB 200415A作为软伽玛中继器（SGR）的巨型耀斑（GF）的另一种解释。这种解释得到非典型硬能谱的支持。此外，根据脉冲串在\（E_ {p，i} {-} E_ {iso} \）上的位置（能量谱中最大值的位置\（\ nu F _ {\ nu} \）源帧中的时间取决于总能量的各向同性当量（以伽马射线发射）和\（T_ {90，i} {-} EH \）（源帧中的持续时间取决于参数\（EH = E_ {p，i，2} E_ {iso，51} ^ {-0.4} \））图中，假定GRB 200415A与银河系NGC 253有关联，就明确地归类为磁星的巨大耀斑。在这些图中，银河系中已知的巨大耀斑和附近星系中的巨大耀斑候选者组成了一个明确的组，其中包括GRB 200415A。