A Deep Chandra X-Ray Observatory Study of the Millisecond Pulsar Population in the Globular Cluster Terzan 5
A Deep Chandra X-Ray Observatory Study of the Millisecond Pulsar Population in the Globular Cluster Terzan 5
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深部钱德拉 X 射线天文台对球状星团 Terzan 5 中毫秒脉冲星群的研究
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发表时间：
2020
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通讯作者：
I. Stairs
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作者：
S. Bogdanov;A. Bahramian;C. Heinke;P. Freire;J. Hessels;S. Ransom;I. Stairs
我们分析了2000年至2016年期间积累的钱德拉X射线天文台先进电荷耦合成像光谱仪记录的745.8 k丰富的银河系球状星团Terzan 5中毫秒脉冲星的数据。在38个具有精确位置的毫秒脉冲星中，有8个被发现具有合理的X射线源匹配。尽管有很深的曝光，但其余的MSP要么被边缘探测到，要么没有明显的X射线对应物，这可以归因于旋转动力MSP的典型软热谱，它被朝向星团的高插入吸收柱(∼1022 cm−2)强烈衰减，在某些情况下是严重的源拥挤/混合。对于“红背”MSP双星PSRJ1748−2446P和PSRJ1748−2446ad以及“黑寡妇”双星PSRJ1748−2446O，我们发现了与双星内激波起源一致的轨道周期大幅度X射线变率的明显证据。星系团中的第三个红背MSP，PSRJ1748−2446A，显示了流量在几年的时间尺度上的数量级变化，可能是由于状态转换或来自磁活动的次星的强烈耀斑事件。
We present an analysis of 745.8 ks of archival Chandra X-Ray Observatory Advanced CCD Imaging Spectrometer data accumulated between 2000 and 2016 of the millisecond pulsar (MSP) population in the rich Galactic globular cluster Terzan 5. Eight of the 38 MSPs with precise positions are found to have plausible X-ray source matches. Despite the deep exposure, the remaining MSPs are either marginally detected or have no obvious X-ray counterparts, which can be attributed to the typically soft thermal spectra of rotation-powered MSPs, which are strongly attenuated by the high intervening absorbing column (∼1022 cm−2) toward the cluster, and in some instances to severe source crowding/blending. For the “redback” MSP binaries PSR J1748−2446P and PSR J1748−2446ad and the “black widow” binary system PSR J1748−2446O, we find clear evidence for large-amplitude X-ray variability at the orbital period consistent with an intrabinary shock origin. The third redback MSP in the cluster, PSR J1748−2446A, shows order-of-magnitude variations in flux on timescales of years, possibly due to state transitions or intense flaring episodes from a magnetically active secondary star.