We present the timing and spectral studies of RX J0209.6-7427 during its rare 2019 outburst using observations with the Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC) instruments on the AstroSat satellite. Pulsations having a periodicity of 9.29 s were detected for the first time by the NICER mission in the 0.2-10 keV energy band and, as reported here, by AstroSat over a broad energy band covering 0.3-80 keV. The pulsar exhibits a rapid spin-up during the outburst. Energy resolved folded pulse profiles are generated in several energy bands in 3-80 keV. To the best of our knowledge this is the first report of the timing and spectral characteristics of this Be binary pulsar in hard X-rays. There is suggestion of evolution of the pulse profile with energy. The energy spectrum of the pulsar is determined and from the best fit spectral values, the X-ray luminosity of RX J0209.6-7427 is inferred to be ${1.6}\times 10^{39}$ ergs s$^{-1}$. Our timing and spectral studies suggest that this source has features of an ultraluminous X-ray pulsar in the Magellanic Bridge. Details of the results are presented and discussed in terms of the current ideas.

中文翻译：

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使用 AstroSat 研究 Be/X 射线双星 RX J0209.6-7427 的近期爆发：麦哲伦桥中的新型超亮 X 射线脉冲星？

我们使用软 X 射线望远镜 (SXT) 和 AstroSat 卫星上的大面积 X 射线比例计数器 (LAXPC) 仪器进行观测，介绍了 RX J0209.6-7427 在 2019 年罕见的爆发期间的时序和光谱研究。NICER 任务首次在 0.2-10 keV 能带内检测到周期性为 9.29 s 的脉动，正如本文所报道的，AstroSat 在覆盖 0.3-80 keV 的宽能带内检测到脉动。脉冲星在爆发期间表现出快速旋转。在 3-80 keV 的几个能带中生成能量分辨折叠脉冲轮廓。据我们所知，这是关于这颗 Be 双星脉冲星在硬 X 射线中的时序和光谱特征的首次报告。有关于脉冲轮廓随能量演变的建议。确定脉冲星的能谱，并根据最佳拟合谱值，推断出 RX J0209.6-7427 的 X 射线光度为 ${1.6}\times 10^{39}$ ergs s$^{- 1}$。我们的时间和光谱研究表明，该源具有麦哲伦桥中超亮 X 射线脉冲星的特征。结果的详细信息将根据当前的想法进行呈现和讨论。