Abstract

The magnetar SGR J1745–2900 located in the vicinity of the supermassive black hole Sgr A\({}^{\star}\) was detected during its X-ray outburst with the Swift/XRT telescope in April 2013. For several months after its detection the source was observed with the NuSTAR observatory, which allowed pulsations with a period \({\sim}3.76\) s to be recorded. Using these observations, we have studied in detail the dependence of the pulse profile and the pulsed fraction on the energy and intensity of the magnetar. The pulsed fraction in the 3–5 and 5–10 keV energy bands is shown to be 40–50\(\%\), slightly increasing with decreasing flux. We have performed phase-resolved spectroscopy for the source in the energy range from 3 to \({\sim}40\) keV and show that the temperature of the emitting regions remains fairly stable during the pulse, while their apparent size changes significantly with phase.

中文翻译：

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基于 NuSTAR 天文台数据的磁星 SGR J1745-2900 的相分辨光谱

摘要

位于超大质量黑洞 Sgr A \({}^{\star}\)附近的磁星 SGR J1745-2900在 2013 年 4 月使用 Swift/XRT 望远镜的 X 射线爆发期间被探测到。 NuSTAR 天文台对它的探测进行了观测，该天文台允许记录周期为\({\sim}3.76\) s 的脉动。使用这些观察结果，我们详细研究了脉冲轮廓和脉冲分数对磁星能量和强度的依赖性。3–5 和 5–10 keV 能带中的脉冲分数显示为 40–50 \(\%\)，随着通量的减少而略有增加。我们已经对能量范围从 3 到\({\sim}40\) keV 并表明发射区域的温度在脉冲期间保持相当稳定，而它们的表观尺寸随相位发生显着变化。