论文标题
来自附近射电星系中的磁磁盘的高能伽马射线
High-energy Gamma-rays from Magnetically Arrested Disks in Nearby Radio Galaxies
论文作者
论文摘要
来自附近射电星系的GEV伽马射线的起源尚不清楚。提出了可能的情况，该磁盘（BHS）周围被磁性逮捕的磁盘（MAD）发射为可能的情况。通过磁重新连接和随机湍流加速，颗粒在MAD中加速。我们从Fermi 4LAC-DR2目录中挑选出GEV频段中的15个最亮的射电星系，并应用MAD模型。我们发现，如果积聚率低于爱丁顿速率的0.1％，则可以通过MAD模型解释GEV频段中的数据。对于较高的吸积率，由于大量的低能量光子，GEV伽玛射线被两光子相互作用所吸收。如果我们假设通过磁重新连接对电子加热速率进行另一项提议的处方，则MAD模型无法重现我们大多数样品的GEV数据。这表明电子加热速率至关重要。我们还将MAD模型应用于SGR A*，并发现在银河中心观察到的GEV伽马射线并非来自SGR A*的Mad。我们从SGR A*估算了宇宙射线强度，但是它太低了，无法解释地球上的高能量宇宙射线强度。
The origins of the GeV gamma-rays from nearby radio galaxies are unknown. Hadronic emission from magnetically arrested disks (MADs) around central black holes (BHs) is proposed as a possible scenario. Particles are accelerated in the MAD by magnetic reconnection and stochastic turbulence acceleration. We pick out the fifteen brightest radio galaxies in the GeV band from the Fermi 4LAC-DR2 catalog and apply the MAD model. We find that we can explain the data in the GeV bands by the MAD model if the accretion rate is lower than 0.1% of the Eddington rate. For a higher accretion rate, GeV gamma-rays are absorbed by two-photon interaction due to copious low-energy photons. If we assume another proposed prescription of the electron heating rate by magnetic reconnection, the MAD model fails to reproduce the GeV data for the majority of our sample. This indicates that the electron heating rate is crucial. We also apply the MAD model to Sgr A* and find that GeV gamma-rays observed at the Galactic center do not come from the MAD of Sgr A*. We estimate the cosmic ray intensity from Sgr A*, but it is too low to explain the high-energy cosmic ray intensity on Earth.
