论文标题
在低质量X射线二进制4U 1730--22中发现584.65 Hz爆发振荡
Discovery of a 584.65 Hz Burst Oscillation in the Low Mass X-Ray Binary 4U 1730--22
论文作者
论文摘要
I型X射线爆发振荡由低质量X射线二进制（LMXB）的中子星（NS）表面上释放的热核能提供动力，其中爆发振荡频率接近NS旋转速率。在这项工作中，我们报告了在3月20日2022年3月20日，\ textIt {中子星形构成Explorer}（\ textit explorer}（\ textit}（\ textit {niceer}），我们报告了I型I X射线爆发的冷却尾巴的检测，在584.65 Hz的检测中。振荡信号显示出强大的Leahy功率，$ p _ {\ rm m} \ sim54.04 $，大约584.65 Hz，该试验分别具有单个试验和多个试验的置信度，分别为$7.05σ$和$4.78σ$。 0.2--10 keV带中振荡的折叠脉冲轮廓显示出正弦形状，分数振幅RMS为$（12.5 \ pm1.8）\％$。我们发现振荡频率显示出微不足道的向上漂移，即在冷却尾巴期间小于0.3 Hz，与在积聚毫秒X射线脉冲星（AMXP）中出现的行为相似，并且表明源可能是以1.71毫秒为单位的AMXP旋转。
Type-I X-ray burst oscillations are powered by thermonuclear released on the neutron star (NS) surface in low mass X-ray binaries (LMXBs), where the burst oscillation frequencies are close to the NS spin rates. In this work, we report the detection of oscillation at 584.65 Hz during the cooling tail of a type-I X-ray bursts observed from the accreting NS LMXB 4U~1730--22 in 2022 March 20, by the \textit{ Neutron star Interior Composition Explorer} (\textit{NICER}) telescope. The oscillation signal showed a strong Leahy power, $P_{\rm m}\sim54.04$, around 584.65 Hz, which has single trial and multiple trials confidence levels of $7.05σ$ and $4.78σ$, respectively. The folded pulse profile of the oscillation in the 0.2--10 keV band showed a sinusoidal shape with the fraction amplitude rms of $(12.5\pm1.8)\%$. We found the oscillation frequency showed insignificant upward drifting, i.e., less than 0.3 Hz, during the cooling tail, similar as the behavior appearing in accreting millisecond X-ray pulsars (AMXP), and indicate the source could be an AMXP spinning at 1.71 ms.
