We report the results of broadband observations of distant blazar PKS 0537-286 (z = 3.1) using data spanning more than ten years from the Fermi Large Area Telescope together with Swift UVOT/XRT archival data taken between 2005 and 2017. In the γ -ray band, the peak flux above 100 MeV, F$_{γ}$ = (6 23 ± 0 56) ∙ 10$^{-7}$ photon cm$^{-2}$ s$^{-1}$ observed on MJD 57874 within one week, corresponds to L$_{γ}$ = 2 46 ∙ 10$^{49}$ erg s$^{-1}$ isotropic γ -ray luminosity. The Swift XRT data analyses show that the X-ray emission is characterized by a significantly hard photon index, Γ$_{X-ray}$ ≤ 1.3 , and an X-ray flux of 4 ∙ 10$^{-12}$ erg cm$^{-2}$ s$^{-1}$, which is almost constant over twelve years. The spectral energy distribution is modeled within one-zone leptonic models assuming the emission region is within the broad-line region. The observed X-ray and γ -ray data are modeled as inverse Compton scattering of (i) only synchrotron photons and (ii) synchrotron and external photons on the electron population that produces the radioto-optical emission. The modeling shows that the nonthermal electrons in the jet of PKS 0537-286 have a hard power-law index (<1.9) and that the jet should be particle dominated with a luminosity within 10$^{45}$-10$^{46}$ erg s$^{-1}$.

中文翻译：

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远距离Blazar PKS 0537-286的多波长研究

我们报告了使用费米大面积望远镜超过十年的数据以及 2005 年至 2017 年期间拍摄的 Swift UVOT/XRT 档案数据对遥远耀变体 PKS 0537-286 (z = 3.1) 进行宽带观测的结果。在 γ -射线带，100 MeV以上的峰值通量，F$_{γ}$ = (6 23 ± 0 56) ∙ 10$^{-7}$ photon cm$^{-2}$ s$^{-1}一周内在 MJD 57874 上观测到的 $，对应于 L$_{γ}$ = 2 46 ∙ 10$^{49}$ erg s$^{-1}$ 各向同性 γ 射线光度。Swift XRT 数据分析表明，X 射线发射具有显着的硬光子指数，Γ$_{X-ray}$ ≤ 1.3 和 X 射线通量为 4 ∙ 10$^{-12}$ erg cm$^{-2}$ s$^{-1}$，在十二年内几乎保持不变。假设发射区域在宽线区域内，光谱能量分布在单区轻子模型内建模。观察到的 X 射线和 γ 射线数据被建模为 (i) 仅同步加速器光子和 (ii) 同步加速器和外部光子对产生无线电光发射的电子群的逆康普顿散射。建模表明，PKS 0537-286 喷流中的非热电子具有硬幂律指数 (<1.9)，并且该喷流应该是粒子主导的，光度在 10$^{45}$-10$^{ 46}$ 尔格 s$^{-1}$。