论文标题
中子恒星低质量X射线二进制CEN X-4的Meerkat无线电观察以低积聚速率
MeerKAT radio observations of the neutron star low-mass X-ray binary Cen X-4 at low accretion rates
论文作者
论文摘要
Centaurus X-4（CEN X-4）是一个相对附近的中子恒星低质量X射线二进制，在1969年和1979年显示爆发，但此后没有显示出完整的爆发。由于其接近性和持续的静止周期，它是研究静态中子恒星低质量X射线二进制中吸积和喷射弹药之间的耦合的主要目标。在这里，我们在1.3 GHz的CEN X-4上介绍了四个Meerkat无线电观察结果，并结合了更好和Swift X射线监测。在第一个也是最敏感的观察过程中，CEN X-4处于完全静止的X射线状态。三人之后，较短的观察结果是2021年1月的短暂X射线活动，被称为“误用”爆发。在四个Meerkat观察中均未检测到CEN X-4。我们将这些无线电插图放在X射线 - 无线电亮度图上，从而改善了早期静止无线电研究的两种光泽度之间相关性的约束。我们确认CEN X-4比过渡毫米脉冲脉冲PSR J1023+0038在相同的X射线光度下是无线电的无线电。我们更普遍地讨论了在低X射线光度下积聚中子星的无线电行为，最后评论未来的观察活动。
Centaurus X-4 (Cen X-4) is a relatively nearby neutron star low-mass X-ray binary that showed outbursts in 1969 and 1979, but has not shown a full outburst since. Due to its proximity and sustained period of quiescence, it is a prime target to study the coupling between accretion and jet ejection in quiescent neutron star low-mass X-ray binaries. Here, we present four MeerKAT radio observations at 1.3 GHz of Cen X-4, combined with NICER and Swift X-ray monitoring. During the first and most sensitive observation, Cen X-4 was in a fully quiescent X-ray state. The three later and shorter observations targeted a brief period of faint X-ray activity in January 2021, which has been referred to as a 'mis-fired' outburst. Cen X-4 is not detected in any of the four MeerKAT observations. We place these radio non-detections on the X-ray -- radio luminosity diagram, improving the constraints on the correlation between the two luminosities from earlier quiescent radio studies. We confirm that Cen X-4 is radio fainter than the transitional milli-second pulsar PSR J1023+0038 at the same X-ray luminosity. We discuss the radio behaviour of accreting neutron stars at low X-ray luminosity more generally and finally comment on future observing campaigns.
