论文标题
在合并星系群集SPT-CL J2031-4037中，硬X射线排放的可能非热起源
Possible non-thermal origin of the hard X-ray emission in the merging galaxy cluster SPT-CL J2031-4037
论文作者
论文摘要
在高能量X射线状态下的星系群中的非热发射已使用各种工具进行了搜索，但是尚未发现该排放的检测显着性是边际或有争议的。利用Nustar的独特能力将X射线聚焦于硬能带上，我们对合并的Galaxy群集SPT-CL J2031-4037进行了238 KS Nustar观察的详细分析，以搜索非热逆转录康普顿发射。我们对SPT-CL J2031-4037的光谱分析表明，群集的硬X射线发射可以用非热成分来描述，尽管我们不能完全排除这种硬发射的纯粹的热起源。包括统计和系统的不确定性在内，我们的最佳模型拟合会产生20-80 KEV的非热通量，$ 3.93 _ { - 1.10}^{+1.24} \ times 10^{ - 12} $ 12} $ erg S $^s $^{ - 1} $ CM $^{ - 2} $。估计的非热通量与使用Nustar和其他X射线仪器在其他星系簇中发现的通量相当。使用这种非热通量与群集的现有无线电数据，我们估计一个体积平均的磁场强度约为0.1-0.2 $ $ g。
Non-thermal emission from clusters of galaxies at the high-energy X-ray regime has been searched with various instruments, but the detection significance of this emission has yet been found to be either marginal or controversial. Taking advantage of NuSTAR's unique capability to focus X-rays in the hard energy band, we present a detailed analysis of 238 ks NuSTAR observations of the merging galaxy cluster SPT-CL J2031-4037, searching for non-thermal inverse Compton emission. Our spectral analysis of SPT-CL J2031-4037 shows a possibility that the hard X-ray emission of the cluster can be described by a non-thermal component, though we cannot completely rule out a purely thermal origin for this hard emission. Including the statistical and systematic uncertainties, our best model fit yields a 20-80 keV non-thermal flux of $3.93_{-1.10}^{+1.24} \times 10^{-12}$ erg s$^{-1}$ cm$^{-2}$. The estimated non-thermal flux is comparable to those found in other galaxy clusters using NuSTAR and other X-ray instruments. Using this non-thermal flux with the existing radio data of the cluster, we estimate a volume-averaged magnetic field strength in the range of around 0.1-0.2 $μ$G.
