标题： B1853+01周围的脉冲星风星云X射线图像 显示英文标题

标题： The pulsar wind nebula around B1853+01 in X-rays

摘要： 我们报告了对位于W44超新星遗迹（SNR）内部的脉冲星风星云（PWN）相关脉冲星PSR B1853+01的X射线观测结果，这些观测使用了\textit{钱德拉}、\textit{XMM-Newton}和\textit{NuSTAR}进行。 之前的X射线观测揭示了位于W44热X射线发射区域南部边缘的快速移动脉冲星PSR B1853+01，以及一个延伸的尾部结构，跟随在脉冲星之后。 我们的分析还显示，在脉冲星前方约1\arcmin （$\sim$1.0 pc，距离为3.2 kpc）处存在一个“流出”特征。 在更大的尺度上，整个PWN似乎被一个微弱的、弥散的X射线发射结构包围。 这个结构的南部区域呈现出与脉冲星前方的“喷流”特征相同的异常形态，并沿着脉冲星自行方向延伸$\sim 6$ \arcmin ($\sim$ 5 pc)。 在本报告中，对PSR B1853+01周围的不同扩展区域进行了空间分辨的光谱分析。 为了获得$0.65_{+0.46}^{-0.42} \times 10^{22} ~\textrm{cm}^{-2}$的更新柱密度值，对“喷流”区域进行幂律拟合，得到光谱指数$\Gamma \approx 1.24_{+0.23}^{-0.24}$，这比脉冲星（$\Gamma \approx 1.87_{+0.48}^{-0.43}$）和脉冲星尾部（$\Gamma \approx 2.01_{+0.39}^{-0.38}$）的光谱指数要显著硬。 我们认为，“喷流”结构和周围的类晕状X射线辐射可能由逃逸出PSR B1853+01周围脉冲星风云的高能粒子产生，这一情景最近也已被提出用于其他具有喷流结构和/或TeV晕的弓形激波脉冲星风云。 显示英文摘要

摘要： We report on the results of a comprehensive analysis of X-ray observations carried out with \textit{Chandra}, \textit{XMM-Newton} and \textit{NuSTAR} of the pulsar wind nebula (PWN) associated with PSR B1853+01, located inside the W44 supernova remnant (SNR). Previous X-ray observations unveiled the presence of a fast-moving pulsar, PSR B1853+01, located at the southern edge of the W44 thermal X-ray emission region, as well as an elongated tail structure trailing the pulsar. Our analysis reveals, in addition, the presence of an ``outflow'' feature ahead of the pulsar extending for about 1 \arcmin ($\sim$ 1.0 pc at the distance of 3.2 kpc). At larger scales, the entire PWN seems to be surrounded by a faint, diffuse X-ray emission structure. The southern part of this structure displays the same unusual morphology as the ``outflow'' feature ahead of the pulsar, and extends along $\sim 6$ \arcmin ($\sim$ 5 pc) in the direction of the pulsar proper motion. In this report, a spatially-resolved spectral analysis for the different extended regions around PSR B1853+01 is carried out. For an updated value of the column density of $0.65_{+0.46}^{-0.42} \times 10^{22} ~\textrm{cm}^{-2}$, a power-law fit to the ``outflow'' region yields a spectral index $\Gamma \approx 1.24_{+0.23}^{-0.24}$, which is significantly harder than that of the pulsar ($\Gamma \approx 1.87_{+0.48}^{-0.43}$) and the pulsar tail ($\Gamma \approx 2.01_{+0.39}^{-0.38}$). We argue that both the ``outflow'' structure and the surrounding halo-like X-ray emission might be produced by high-energy particles escaping the PWN around PSR B1853+01, a scenario recently suggested also for other Bow-shock PWNe with jet-like structures and/or TeV halos.