标题： X射线和近红外观测中的中年脉冲星B1055-52，其多波长光谱和自行 显示英文标题

标题： X-ray and near-infrared observations of the middle-aged pulsar B1055-52, its multiwavelength spectrum, and proper motion

摘要： 先前对中年$\gamma$射线、X射线和射电脉冲星 B1055-52 的观测显示了一些异常，例如疑似 X 射线流量和光谱参数的变化，紫外线（UV）光谱中假设的热成分相对于 X 射线热光谱的 Rayleigh-Jeans 延伸部分存在较大的过量，以及在光学和 X 射线波段之间非热光谱成分可能存在两个断裂点。 我们使用 XMM-Newton 观测设备在 X 射线波段和哈勃空间望远镜在近红外（NIR）波段对 PSR B1055-52 进行了观测。 XMM-Newton 观测的分析不支持脉冲星 X 射线流量和宽波段 X 射线光谱长期变化的观点。 采用比之前 XMM-Newton 观测受背景噪声影响更小的观测模式，我们将幂律（PL）光谱指数限制为 $\alpha_X=-0.57^{+0.26}_{-0.25} $ ($F_{\nu} \propto \nu^{\alpha}$) 在 3-10 keV 能量范围内。 从 NIR-光学数据中，我们得到色指数 $E(B-V)=0.03$ mag 的 PL 倾斜度为 $\alpha_O= -0.24 \pm 0.10$。 NIR-光学和 X 射线非热光谱的倾斜度和流量表明，NIR 到 X 射线辐射可以用相同的 PL 描述，并由相同机制产生，这与脉冲星的$\gamma$射线辐射不同。 紫外线热成分相对于 X 射线热成分延伸部分的过量变小了，但并未消失，表明整体表面温度并不均匀。 近红外数据还使我们能够准确测量自行，其值为$\mu_\alpha =47.5\pm 0.7\,{\rm mas\,yr}^{-1}$和$\mu_\delta = -8.7 \pm 0.7 \,{\rm mas\,yr}^{-1}$。 显示英文摘要

摘要： Previous observations of the middle-aged $\gamma$-ray, X-ray, and radio pulsar B1055-52 indicated some peculiarities, such as a suspected changing of the X-ray flux and spectral parameters, a large excess of the alleged thermal component of the ultraviolet (UV) spectrum over the Rayleigh-Jeans extension of the X-ray thermal spectrum, and a possible double break in the nonthermal spectral component between the optical and X-ray bands. We observed PSR B1055-52 with the XMM-Newton observatory in X-rays and the Hubble Space Telescope in near-infrared (NIR). The analysis of the XMM-Newton observations does not support the notion of long-term changes in the X-ray flux and broad-band X-ray spectrum of the pulsar. Using an observing mode less affected by background noise than the previous XMM-Newton observations, we constrain the power-law (PL) spectral index as $\alpha_X=-0.57^{+0.26}_{-0.25} $ ($F_{\nu} \propto \nu^{\alpha}$) in the energy band 3-10 keV. From the NIR-optical data we obtain a PL slope $\alpha_O= -0.24 \pm 0.10$ for the color index $E(B-V)=0.03$ mag. The slopes and fluxes of the NIR-optical and X-ray nonthermal spectra suggest that the NIR through X-ray emission can be described by the same PL and is generated by the same mechanism, unlike the pulsar's $\gamma$-ray emission. The excess of the UV thermal component over the extension of the X-ray thermal component became smaller but did not disappear, indicating a non-uniformity of the bulk surface temperature. The NIR data also enable us to accurately measure the proper motion with values $\mu_\alpha =47.5\pm 0.7\,{\rm mas\,yr}^{-1}$ and $\mu_\delta = -8.7 \pm 0.7 \,{\rm mas\,yr}^{-1}$.