论文标题
Vela X-1中的回旋共振散射特征的变化揭示了Insight-HXMT
Variations of cyclotron resonant scattering features in Vela X-1 revealed with Insight-HXMT
论文作者
论文摘要
我们使用Insight-HXMT在2019年和2020年进行的观察结果介绍了高质量X射线二进制Vela X-1的详细研究，集中于时间分析和光谱研究，包括脉冲相分辨光谱。基本和第一个谐波分别为〜21-27 KEV和43-50 keV。我们提出了光谱参数的演变，发现两个线质心能比E2/e1从MJD 58900之前的〜2演变为〜1.7。谐波回旋线能量与亮度无关，但是基本线能表现出与X射线光度的正相关，这表明Vela X-1位于亚临界策略积聚方案中。另外，进行Vela X-1中的脉冲相分辨光谱。 CRSF和连续参数在脉冲相位均显示出强大的可变性，而峰阶段附近的两个线能的比率大约为2个，并且在非高峰期周围向下降至〜1.6。吸收柱密度的长期显着变化及其在脉冲相中的演变可能意味着中子恒星附近存在块状风结构。
We present a detailed study of the high mass X-ray binary Vela X-1, using observations performed by Insight-HXMT in 2019 and 2020, concentrating on timing analysis and spectral studies including pulse phase-resolved spectroscopy. The cyclotron line energy is found to be at ~21-27 keV and 43-50 keV for the fundamental and first harmonic, respectively. We present the evolution of spectral parameters and find that two line centroid energy ratio E2/E1 evolved from ~2 before MJD 58900 to ~1.7 after that. The harmonic cyclotron line energy has no relation to the luminosity but the fundamental line energy shows a positive correlation with X-ray luminosity, suggesting that Vela X-1 is located in the sub-critical accreting regime. In addition, the pulse phase-resolved spectroscopy in Vela X-1 is performed. Both the CRSF and continuum parameters show strong variability over the pulse phase with the ratio of two line energies about 2 near the peak phases, and down to ~1.6 around off-peak phases. Long-term significant variations of the absorption column density and its evolution over the pulse phase may imply the existence of the clumpy wind structure near the neutron star.
