论文标题
RX J0209.6-7427的2019年超级 - 埃德丁顿爆发：检测磁场强度的脉动和约束
The 2019 super-Eddington outburst of RX J0209.6-7427: Detection of pulsations and constraints on the magnetic field strength
论文作者
论文摘要
2019年11月，Maxi检测到已知的BE X射线二进制系统RX J0209.6-7427的X射线爆发，位于小麦哲伦云的外翼。我们跟随系统的爆发，并以9.3 s的周期发现了X射线脉动。我们分析了使用Nustar和NoTER获得的同时获得的X射线数据，使我们能够表征光谱并提供了其降压光度亮度的准确估计。在爆发期间，系统的最大宽带X射线光度达到$ 1-2 \ times10^{39} $ erg/s，因此超过了约一个数量级的典型1.4 $ m _ {\ odot} $ MOSS NECTRINMEN STAR（NS）的Eddington限制。用费米/GBM和NOTER监测观察结果使我们能够研究NS的自旋演变，并将其与标准积聚扭矩模型进行比较。我们发现，NS磁场应为$ 3 \ times10^{12} $G。我们得出的结论是，RX J0209.6-7427展示了从Magellanic云中的Be X射线二元脉冲星中观察到的最亮的爆发之一，从而达到了与2016年爆炸率相似的Lumininosty水平。尽管RX J0209.6-7427的超级 - 埃德丁顿光度，但NS似乎只有中等的磁场强度。
In November 2019, MAXI detected an X-ray outburst from the known Be X-ray binary system RX J0209.6-7427 located in the outer wing of the Small Magellanic Cloud. We followed the outburst of the system with NICER which led to the discovery of X-ray pulsations with a period of 9.3 s. We analyzed simultaneous X-ray data obtained with NuSTAR and NICER allowing us to characterize the spectrum and provide an accurate estimate of its bolometric luminosity. During the outburst the maximum broadband X-ray luminosity of the system reached $1-2\times10^{39}$ erg/s, thus exceeding by about one order of magnitude the Eddington limit for a typical 1.4 $M_{\odot}$ mass neutron star (NS). Monitoring observations with Fermi/GBM and NICER allowed us to study the spin evolution of the NS and compare it with standard accretion torque models. We found that the NS magnetic field should be of the order of $3\times10^{12}$ G. We conclude that RX J0209.6-7427 exhibited one of the brightest outbursts observed from a Be X-ray binary pulsar in the Magellanic Clouds, reaching similar luminosity level to the 2016 outburst of SMC X-3. Despite the super-Eddington luminosity of RX J0209.6-7427, the NS appears to have only a moderate magnetic field strength.
