论文标题
螃蟹星云的宽带能量光谱及其明显扩展的现象学建模
Phenomenological modelling of the Crab Nebula's broad band energy spectrum and its apparent extension
论文作者
论文摘要
螃蟹星云从无线电到最有力的光子发出明亮的非热辐射。自1970年代初以来，来自流体动力立场冲击的脉冲星的相对论风的潜在物理模型一直保持不变。在此模型中，预期减震器下游的环形磁场会增加。我们介绍了一个详细的辐射模型，以计算非热同步子和逆康普顿以及自同时的热粉尘发射，以定量地与观察数据进行比较。对电子和种子场密度的径向依赖性进行特殊护理。辐射模型用于估计星云中电子和灰尘的参数。基于$χ^2 $最小化的组合拟合可成功再现所使用的完整数据集。对于最合适的模型，磁场的能量密度在粒子能量密度上占主导地位，直至$ \ \ \ \ \ r_s $（$ r_s $：与PULSAR的终止冲击的距离）。非常高的能量（VHE：$ e> 100 $ GEV）伽马射线光谱对磁场的径向依赖性设定了最强的约束：$ b（r）=（264 \ pm9）〜μ \ mathrm {g}（r/r/r_s）重建的磁场及其径向依赖性表明，在终止冲击时，po和动能通量的比率约为0.1 $，$ \ \ \ \ \ 30 $的比现在比现在大。因此，星云的限制将需要其他机制来减慢流过的流动。磁场可能耗散的小规模湍流激发。
The Crab Nebula emits bright non-thermal radiation from radio to the most energetic photons. The underlying physical model of a relativistic wind from the pulsar terminating in a hydrodynamic standing shock remains unchanged since the early 1970s. In this model, an increase of the toroidal magnetic field downstream from the shock is expected. We introduce a detailed radiative model to calculate non-thermal synchrotron and inverse Compton as well as thermal dust emission self-consistently to compare quantitatively with observational data. Special care is given to the radial dependence of electron and seed field density. The radiative model is used to estimate the parameters of electrons and dust in the nebula. A combined fit based upon a $χ^2$ minimisation reproduces successfully the complete data set used. For the best-fitting model, the energy density of the magnetic field dominates over the particle energy density up to a distance of $\approx 1.3~r_s$ ($r_s$: distance of the termination shock from the pulsar). The very high energy (VHE: $E>100$ GeV) gamma-ray spectra set the strongest constraints on the radial dependence of the magnetic field: $B(r)=(264\pm9)~μ\mathrm{G} (r/r_s)^{-0.51\pm0.03}$. The reconstructed magnetic field and its radial dependence indicates a ratio of Poynting to kinetic energy flux $σ\approx 0.1$ at the termination shock, $\approx 30$ times larger than estimated up to now. Consequently, the confinement of the nebula would require additional mechanisms to slow down the flow through e.g. excitation of small-scale turbulence with possible dissipation of magnetic field.
