论文标题
检测SNR HB9周围的伽马射线及其对扩散冲击历史的影响
Detection of gamma rays around SNR HB9 and its implication to the diffusive shock-acceleration history
论文作者
论文摘要
我们从\ textit {fermi} -lat 12年观测值中分析了超新星残留（SNR）HB9（G160.9+2.6）附近的GEV伽马射线发射数据，以量化SNR中扩散性冲击加速度（DSA）的演变。在HB9附近，有分子云的位置与视线中的SNR壳不一致。我们检测到高于1 〜GEV的显着伽马射线发射在空间上与两个突出的云区域一致，以及SNR壳的发射，后者与以前的研究结果一致。每个区域中1〜GEV上方的能量谱拟合了$ dn/de \ propto e^{ - γ} $的简单幂律函数。拟合结果表明，与$γ$ = $γ$ = $ 1.84 \ pm 0.18 $和$ 1.84 \ pm 0.14 $的幂律指数的光谱相比，$γ$ = $ 2.55 \ pm 0.10 $。发现来自云区域的观察到的光谱与源自从SNR HB9逃脱的质子的理论上预期的伽马射线排放是一致的，在该质子中，粒子可以加速到现在的壳能量高于目前的壳。 SNR附近的最终扩散系数与银河平均值的扩散系数相当。
We analyze the GeV gamma-ray emission data from the vicinity of the supernova remnant (SNR) HB9 (G160.9+2.6) from the \textit{Fermi}-LAT 12-year observations to quantify the evolution of diffusive shock acceleration (DSA) in the SNR. In the vicinity of HB9, there are molecular clouds whose locations do not coincide with the SNR shell in the line of sight. We detect significant gamma-ray emissions above 1~GeV spatially coinciding with the two prominent cloud regions, as well as a emission from the SNR shell, the latter of which is consistent with the results of previous studies. The energy spectrum above 1~GeV in each region is fitted with a simple power-law function of $dN/dE \propto E^{-Γ}$. The fitting result indicates harder spectra with power-law indices of $Γ$ = $1.84 \pm 0.18$ and $1.84 \pm 0.14$ than that at the SNR shell with $Γ$= $2.55 \pm 0.10$. The observed spectra from the cloud regions are found to be consistent with the theoretically expected gamma-ray emissions originating in the protons that escaped from SNR HB9, where particles can be accelerated up to higher energies than those at the shell at present. The resultant diffusion coefficient in the vicinity of the SNR is comparable to that of the Galactic mean.
