标题： X射线晕 Around 中年脉冲星的探测前景与eROSITA 显示英文标题

标题： Prospect of Detecting X-Ray Halos Around Middle-Aged Pulsars with eROSITA

摘要： 通过HAWC合作组对Geminga和Monogem脉冲星的扩展TeV$\gamma$-射线辐射（被称为“TeV晕”）的探测，表明在中等年龄脉冲星周围的晕状结构可能是普遍存在的。 高于10 TeV的$\gamma$-射线被认为来源于脉冲星晕中相对论电子/正电子对宇宙微波背景光子的逆康普顿散射。 同时，这些电子和正电子可以在星际磁场中产生X射线同步辐射，从而在X射线波段产生弥漫辐射（即X射线晕）。 在这里，我们研究了利用eROSITA从ATNF脉冲星目录中具有大于数万年特征年龄的10个中等年龄脉冲星探测X射线晕的前景。 假设一个基准值（即$B = 3 \rm \, \mu G$）作为磁场强度，大多数X射线晕被发现足够明亮，可以在其四年全天巡天的能量范围0.5-2 keV内被eROSITA探测到。 在这些脉冲星晕中，有三个预计会产生超过eROSITA第一次全天巡天灵敏度的X射线通量。 鉴于良好的角分辨率和大视场，eROSITA有望能够测量从亚秒差距尺度到数十秒差距尺度的X射线晕的空间分布。 X射线晕的强度剖面对于限制脉冲星晕中的磁场以及扩散系数的能量依赖性非常有用。 显示英文摘要

摘要： The detection of extended TeV $\gamma$-ray emission (dubbed "TeV halos") from Geminga and Monogem pulsars by HAWC collaboration implies that the halo-like morphologies around middle-aged pulsars may be common. The $\gamma$-rays above 10 TeV are thought to arise from inverse Compton (IC) scattering of relativistic electrons/positrons in the pulsar halos off cosmic microwave background photons. In the meanwhile, these electrons and positrons can produce X-ray synchrotron emission in the interstellar magnetic field, resulting in a diffuse emission in the X-ray band (namely X-ray halos). Here, we study the prospect of detecting X-ray halos with eROSITA from 10 middle-aged pulsars with characteristic age larger than tens of thousands of years in the ATNF pulsar catalog. Assuming a benchmark value (i.e., $B = 3 \rm \, \mu G$) for the magnetic field, most of the X-ray halos are found to be bright enough to be detectable by eROSITA in the energy range of 0.5-2 keV during its four-year all-sky survey. Among these pulsar halos, three are supposed to produce X-ray fluxes above the eROSITA sensitivity of the first all-sky survey. Given the good angular resolution and the large field of view, eROSITA is expected to be able to measure the spatial distribution of the X-ray halos from sub-pc scale up to tens of pc scale. The intensity profiles of the X-ray halos are very useful to constrain the magnetic field and the energy-dependence of the diffusion coefficient in the pulsar halos.