论文标题
$γ$ -Ray观测值GRB 190114C的限制对播放磁场的约束
Constraints on the intergalactic magnetic field from $γ$-ray observations of GRB 190114C
论文作者
论文摘要
宇宙学伽马射线爆发（GRB）的极高能量光子有望与外乳外背景光（EBL）相互作用，并在通过播层间培养基（IgM）传播时产生电子峰值对。然后，这些相对论对将添加分散宇宙微波背景（CMB）光子并发出次级GEV发射。同时，这些对的运动由乳层间磁场（IGMF）偏转，因此次级GEV光子比初级发射时间更晚。已经提出，次级GEV发射的特性可用于约束IGMF。最近，魔术望远镜首次从GRB（GRB 190114C）中检测到TEV伽玛射线发射，其陡峭的$ {\rmγ-ray} $频谱显示出明确的EBL吸收证据。然后，我们用从$ fermi $ -LAT观测值获得的GEV通量限制来限制IGMF。我们发现$> 10^{ - 19.5} $ g的限制为$λ\ leq 1 $ mpc。尽管此限制比使用Blazars获得的限制弱，但它代表了GRB的$ {\ rmγ射线} $观测值的第一个限制，该限制对IGMF提供了独立的约束。我们还发现，对于瞬态$ {\rmγ射线} $源，可以选择一个有利的时间窗口来搜索特定能量的回声发射。
Very high energy photons from cosmological gamma-ray bursts (GRBs) are expected to interact with extragalactic background light (EBL) and produce electron-positron pairs when they propagate through intergalactic medium (IGM). These relativistic pairs will then up-scatter cosmic microwave background (CMB) photons and emit secondary GeV emission. Meanwhile, the motion of these pairs are deflected by intergalactic magnetic field (IGMF), so the secondary GeV photons arrive later than the primary emission. It has been suggested that the properties of the secondary GeV emission can be used to constrain IGMF. Recently, TeV gamma-ray emission has been detected, for the first time, from a GRB (GRB 190114C) by the MAGIC telescope and its steep ${\rm γ-ray}$ spectrum shows a clear evidence of absorption by EBL. We then constrain the IGMF with the GeV flux limit obtained from the $Fermi$-LAT observations. We find a limit of $>10^{-19.5}$ G for the coherence length of $λ\leq 1$ Mpc. Although this limit is weaker than that obtained by using blazars, it represents the first limit from ${\rm γ-ray}$ observations of GRBs, which provides an independent constraint on IGMF. We also find that, for transient ${\rm γ-ray}$ sources, one can choose a favorable time window to search for the echo emission at a particular energy.
