Outflow and Emission Model of Pulsar Wind Nebulae with the Back Reaction of Particle Diffusion
Outflow and Emission Model of Pulsar Wind Nebulae with the Back Reaction of Particle Diffusion
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DOI：
10.3847/1538-4357/aae389
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发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
W. Ishizaki;K. Asano;K. Kawaguchi
中科院分区：
文献类型：
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作者：
W. Ishizaki;K. Asano;K. Kawaguchi
我们提出了一种新的脉冲星风星云（PWN）模型，该模型以自洽的方式解决非热粒子的平流和扩散，以满足动量和能量守恒定律。假设球对称（1D）稳定流出，我们计算整个星云积分的发射光谱和表面亮度的径向轮廓。我们发现颗粒扩散的逆反应改变了流动剖面。光子光谱和表面亮度分布与没有粒子扩散逆反应的模型计算不同。我们的模型应用于两个经过充分研究的 PWNe：3C 58 和 G21.5-0.9。通过拟合这些 PWNe 的光谱，我们确定参数集并计算 X 射线表面亮度的径向分布。对于这两个物体，获得的 X 射线表面亮度和光子指数分布与观测结果非常一致。我们的模型表明，从星云逃逸的粒子对 γ 射线通量有显着贡献。我们的模型预测了比射电星云还要大的 γ 射线晕。
We present a new pulsar wind nebula (PWN) model that solves both advection and diffusion of nonthermal particles in a self-consistent way to satisfy the momentum and energy conservation laws. Assuming spherically symmetric (1D) steady outflow, we calculate the emission spectrum integrating over the entire nebula and the radial profile of the surface brightness. We find that the back reaction of the particle diffusion modifies the flow profile. The photon spectrum and the surface brightness profile are different from the model calculations without the back reaction of the particle diffusion. Our model is applied to the two well-studied PWNe, 3C 58 and G21.5-0.9. By fitting the spectra of these PWNe, we determine the parameter sets and calculate the radial profiles of X-ray surface brightness. For both the objects, obtained profiles of X-ray surface brightness and the photon index are well consistent with observations. Our model suggests that particles that have escaped from the nebula significantly contribute to the γ-ray flux. A γ-ray halo larger than the radio nebula is predicted in our model.