论文标题
SMC X-1中的超晶质调节是否是由翘曲预振盘吸收引起的？
Is superorbital modulation in SMC X-1 caused by absorption in warped precessing accretion disc?
论文作者
论文摘要
我们使用10 suzaku和6个Nustar观测值对SMC X-1进行了SMC X-1的宽带光谱分析。所有状态的频谱都可以通过具有高能量截止的吸收的PowerLaw以及铁发射线以及黑体成分来描述。与其他超级HMXB相比，SMC X -1的Fe K $α$线等效宽度低 - 从高州的少于10 eV到最高$ \ sim $ 270 $ 270 ev。光谱形状取决于通量，而硬X射线光谱随着通量的增加而陡峭。我们还报告了在这16个超轨道状态下的幂律组件的高度归一化。除两个观察结果外，所有仪器的硬X射线中的脉动均被检测到。脉冲曲线接近正弦，两个峰，第二峰的相对强度随着亮度的降低而降低。这些发现表明，SMC X-1中的超轨道调制不是仅是由预进翘曲的吸积盘吸收引起的，并且X射线在不同的超级轨道状态下的X射线中存在固有的变化。我们还指出了一条假定的回旋线，$ \ sim $ 50 kev在\ nustar〜的光谱中，可能的磁场可能为$ \ sim $ 4.2 $ \ times $ 10 $ 10 $^{12} $ g。最后，随着新的脉冲测量结果，在这里报告了新的脉冲测量值，这是Smc x-1的旋转时期的旋转时间，并在199年的时间内增加了一段时间，并在199年的时间内增加了一段时间的播放。
We present a broadband spectral-timing analysis of SMC X-1 at different intensity states of its super-orbital variation using 10 Suzaku and 6 NuSTAR observations. The spectrum in all the states can be described by an absorbed powerlaw with a high energy cutoff and a black-body component along with an iron emission line. Compared to other supergiant HMXBs, the Fe K$α$ line equivalent width is low in SMC X-1 - from less than 10 eV in high state to up to $\sim$ 270 eV in the low states. The spectral shape is dependent on flux with the hard X-ray spectrum steepening with increasing flux. We also report a highly variable normalisation of the power-law component across these 16 super-orbital states. Pulsations in the hard X-rays for both the instruments were detected in all but two observations. The pulse profiles are near sinusoidal with two peaks and the relative intensity of the second peak decreasing with decreasing luminosity. These findings suggest that the super-orbital modulation in SMC X-1 is not caused by absorption in precessing warped accretion disc alone and there are intrinsic changes in X-rays emanating from the neutron star at different super-orbital states. We also note a putative cyclotron line at $\sim$ 50 keV in the \nustar~spectra of three bright states indicating a possible magnetic field of $\sim$ 4.2 $\times$ 10$^{12}$ G. Finally, with the new pulse period measurements reported here, the time base for the secular spin-up of SMC X-1 is increased by thirteen years and the complete pulse period history shows a sudden change in the spin-up trend around 1995.
