与4U 1626-67中通量增强相关的光谱和时间变化
Spectral and temporal changes associated with flux enhancement in 4U 1626-67
摘要：
4U 1626-67是一颗由吸积提供能量的X射线脉冲星，它的X射线亮度在数小时的时间尺度上非常稳定，在数年的时间尺度上强度逐渐变化。在这里，我们报告了4U 1626-67的长期RXTE-ASM光变曲线中X射线强度的显着增加。在Swift-BAT光变曲线中也检测到了X射线通量的类似增强。X射线通量的增加发生在大约100天的长时间内，似乎有两次通量增强。我们利用Rossi X射线定时探测器上的正比计数器阵列和高能X射线定时探测器获得的数据，研究了4U 1626-67在当前增强通量发射状态下的光谱和定时特征。源已进入新的加速旋转阶段，加速旋转速率为4.02（5）$\times$ 10 $^{-13}$ Hz s $^{-1}$。目前的自旋上升率几乎是早期自旋上升和自旋下降趋势的一半。在增强通量状态期间观察到软X射线光子发射的显著过量，这与1990年之前脉冲星自旋上升时期获得的能谱相似。我们还报告检测到的130兆赫的峰值的翅膀和连续的功率谱的形状的变化显着扩大。
英文摘要：
4U 1626-67 is an accretion powered X-ray pulsar that shows remarkably stable X-ray luminosity above hours timescale and gradual intensity variation on a few years timescale. Here we report a significant increase in the X-ray intensity in the long term RXTE-ASM light curve of 4U 1626-67. Similar enhancement in the X-ray flux has also been detected in the Swift-BAT light curve. The increase in the X-ray flux took place over a long period of about 100 days and there appears to be two episodes of flux enhancement. We have investigated the spectral and timing features of 4U 1626-67 during its current state of enhanced flux emission with data obtained from the Proportional Counter Array and the High-Energy X-ray Timing Explorer on board the Rossi X-ray Timing Explorer. The source has entered a new spin-up phase with a spin-up rate of 4.02(5) $\times$ 10$^{-13}$ Hz s$^{-1}$. The present spin-up rate is almost half of the earlier spin-up and spin-down trends. A significant excess in soft X-ray photon emission is observed during the enhanced flux state, which is similar to the energy spectrum obtained during the spin-up era of the pulsar before 1990. We also report detection of a significant broadening in the wings of the 130 mHz peak and a change in the shape of the continuum of the power spectrum.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
