论文标题
Dampe Proton光谱指示附近ISM的慢速扩散区
DAMPE proton spectrum indicates a slow-diffusion zone in the nearby ISM
论文作者
论文摘要
Dampe质子光谱中的硬化和软化特征很可能起源于附近的超新星残留物（SNR）。附近SNR的质子光谱必须在$ \ $ \ tev以下非常困难。为了重现此功能，我们说明宇宙射线（CRS）异常的慢速扩散区（CRS）在考虑到CRS的偶极性各向异性之后，必须存在于局部星际介质（ISM）中。假设在附近ISM中的扩散系数是均匀的，我们表明扩散系数的限制为$ 10^{26} $ cm $^2 $^2 $ s $ s $ s $ s $ s $^{ - 1} $当归一化为1 GEV时，这比Galaxy的平均值小约100倍。我们进一步讨论了缓慢扩散的空间分布，并找到了两个不同的可能性。在一种情况下，SNR距离太阳系几百个parsec，同时SNR和太阳系都必须包括在大型慢速扩散区中。同质扩散属于这种情况。在另一种情况下，SNR非常接近$ \ sim50 $ PC，而慢速扩散区仅在SNR周围受到限制。在后一种情况下，所需的扩散系数更小。这项工作提供了一种研究本地ISM中CR扩散的新方法。
The hardening and softening features in the DAMPE proton spectrum are very likely to be originated from a nearby supernova remnant (SNR). The proton spectrum from the nearby SNR is required to be very hard below $\approx10$ TeV. To reproduce this feature, we illustrate that anomalously slow-diffusion zone for cosmic rays (CRs) must be existed in the local interstellar medium (ISM) after also taking the dipole anisotropy of CRs into account. Assuming that the diffusion coefficient is homogeneous in the nearby ISM, we show that the diffusion coefficient is constrained to the magnitude of $10^{26}$ cm$^2$ s$^{-1}$ when normalized to 1 GeV, which is about 100 times smaller than the average value in the Galaxy. We further discuss the spatial distribution of the slow diffusion and find two distinct possibilities. In one case, the SNR is several hundred of parsecs away from the solar system, meanwhile both the SNR and the solar system are required to be included in a large slow-diffusion zone. The homogeneous diffusion belongs to this case. In the other case, the SNR is very close with a distance of $\sim50$ pc and the slow-diffusion zone is only limited around the SNR. The required diffusion coefficient is further smaller in the latter case. This work provides a new way of studying the CR diffusion in the local ISM.
