论文标题
通过10年的费米LAT数据来推断脉冲脉冲星的脉冲γ射线发射的起源
Inferring the origins of the pulsed gamma-ray emission from the Crab pulsar with 10-year Fermi LAT data
论文作者
论文摘要
上下文：Crab Pulsar是一个明亮的$γ$ ray源，可在光子能量$ \ sim $ 1 TEV处检测到。其相平均和相位分辨的$γ$ - 雷光谱低于10 GEV的指数截止值，而10 GEV以上的GEV显然遵循简单的幂律。目的：我们重新介绍了10年\ emph {fermi}大面积望远镜（LAT）数据的$γ$ ray属性，范围为60 meV-500 GEV。使用相位分辨的光谱，我们研究了负责排放的起源和机制。方法：对不同的能带重构相图，并使用小波分解进一步分析。相位分辨的能光谱与魔术和Veritas等地面仪器的观察结果结合在一起，以实现更大的能量均匀。我们将Power-Law型号拟合到从10 GEV到$ \ sim $ 1 TEV的重叠能源光谱。我们将能量尺度的相对交叉校准与Fermi任务的轨道配对望远镜一起进行了基于空调的伽马射线望远镜之间的相对交叉校准。结果：我们证实了$γ$ ray脉冲形状的能量依赖性，同等的是螃蟹脉冲星的光谱形状的相位依赖性。对于桥相发射，观察到相对较高的$ \ sim $ 8 GEV的相对较高的截止。在第二脉冲峰值上观察到的$ e> $ 10 GEV光谱比其他阶段的峰要难。结论：鉴于螃蟹脉冲星的相分辨光谱形状的多样性，我们暂时提出了一种多农子场景，其中涉及极性cap，外间隙和相对论风区。
Context: The Crab pulsar is a bright $γ$-ray source detected at photon energies up to $\sim$1 TeV. Its phase-averaged and phase-resolved $γ$-ray spectra below 10 GeV exhibit exponential cutoffs while those above 10 GeV apparently follow simple power-laws. Aims: We re-visit the $γ$-ray properties of the Crab pulsar with 10-year \emph{Fermi} Large Area Telescope (LAT) data in the range of 60 MeV--500 GeV. With the phase-resolved spectra, we investigate the origins and mechanisms responsible for the emissions. Methods: The phaseograms are reconstructed for different energy bands and further analysed using a wavelet decomposition. The phase-resolved energy spectra are combined with the observations of ground-based instruments like MAGIC and VERITAS to achieve a larger energy converage. We fit power-law models to the overlapping energy spectra from 10 GeV to $\sim$1 TeV. We include in the fit a relative cross-calibration of energy scales between air-shower based gamma-ray telescopes with the orbital pair-production telescope of the Fermi mission. Results: We confirm the energy-dependence of the $γ$-ray pulse shape, and equivalently, the phase-dependence of the spectral shape for the Crab pulsar. A relatively sharp cutoff at a relatively high energy of $\sim$8 GeV is observed for the bridge-phase emission. The $E>$10 GeV spectrum observed for the second pulse peak is harder than those for other phases. Conclusions: In view of the diversity of phase-resolved spectral shapes of the Crab pulsar, we tentatively propose a multi-origin scenario where the polar-cap, outer-gap and relativistic-wind regions are involved.
