Swings between rotation and accretion power in a binary millisecond pulsar
Swings between rotation and accretion power in a binary millisecond pulsar
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DOI：
10.1038/nature12470
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发表时间：
2013-05
期刊：
影响因子：
64.8
通讯作者：
A. Papitto;C. Ferrigno;E. Bozzo;N. Rea;L. Pavan;L. Burderi;M. Burgay;S. Campana;T. Salvo
中科院分区：
文献类型：
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作者：
A. Papitto;C. Ferrigno;E. Bozzo;N. Rea;L. Pavan;L. Burderi;M. Burgay;S. Campana;T. Salvo
一般认为，低质量双星系统中的中子星可以从伴星星星吸积物质和角动量，并旋转到毫秒级的旋转周期，，。在吸积阶段，系统被称为低质量X射线双星，并观察到明亮的X射线发射。当质量转移的速率在演化的后期阶段降低时，这些双星系统就会拥有一颗射电毫秒脉冲星，其发射是由中子星星的旋转磁场提供动力的。这一演化模型得到了来自几颗吸积中子星的毫秒级X射线脉动探测的支持，也得到了旋转动力毫秒级脉冲星中过去吸积盘的证据的支持。有人提出，在一些这样的系统中，在低质量流入期间，旋转动力脉冲星可能会暂时开启。迄今为止，只有间接的证据表明这种转变被观察到。在这里，我们报告的观测吸积动力，毫秒X射线脉冲从中子星星以前被视为旋转动力的无线电脉冲星。在长达一个月的X射线爆发后的几天内，无线电脉冲再次被探测到。这不仅显示了吸积和旋转动力毫秒双星之间的进化联系，而且一些系统可以在很短的时间尺度上在两种状态之间摇摆。
It is thought that neutron stars in low-mass binary systems can accrete matter and angular momentum from the companion star and be spun-up to millisecond rotational periods,,. During the accretion stage, the system is called a low-mass X-ray binary, and bright X-ray emission is observed. When the rate of mass transfer decreases in the later evolutionary stages, these binaries host a radio millisecond pulsar,whose emission is powered by the neutron star’s rotating magnetic field. This evolutionary model is supported by the detection of millisecond X-ray pulsations from several accreting neutron stars,and also by the evidence for a past accretion disc in a rotation-powered millisecond pulsar. It has been proposed that a rotation-powered pulsar may temporarily switch on,,during periods of low mass inflow in some such systems. Only indirect evidence for this transition has hitherto been observed,,,,. Here we report observations of accretion-powered, millisecond X-ray pulsations from a neutron star previously seen as a rotation-powered radio pulsar. Within a few days after a month-long X-ray outburst, radio pulses were again detected. This not only shows the evolutionary link between accretion and rotation-powered millisecond pulsars, but also that some systems can swing between the two states on very short timescales.