Dips and eclipses in the X-ray binary Swift J1858.6-0814 observed with NICER
D. J. K. Buisson, D. Altamirano, M. Armas Padilla, Z. Arzoumanian, P. Bult, N. Castro Segura, P. A. Charles, N. Degenaar, M. Díaz Trigo, J. van den Eijnden, F. … 展开作者
D. J. K. Buisson, D. Altamirano, M. Armas Padilla, Z. Arzoumanian, P. Bult, N. Castro Segura, P. A. Charles, N. Degenaar, M. Díaz Trigo, J. van den Eijnden, F. Fogantini, P. Gandhi, K. Gendreau, J. Hare, J. Homan, C. Knigge, C. Malacaria, M. Mendez, T. Muñoz Darias, M. Ng, M. Özbey Arabacı, R. Remillard, T. E. Strohmayer, F. Tombesi, J. A. Tomsick, F. Vincentelli, D. J. Walton
We present the discovery of eclipses in the X-ray light curves of the X-ray binary Swift J1858.6-0814. From these, we find an orbital period of $P=76841.3_{-1.4}^{+1.3}$ s ($\approx21.3$ hours) and an eclipse duration of $t_{\rm ec}=4098_{-18}^{+17}$ s ($\approx1.14$ hours). We also find several absorption dips during the pre-eclipse phase. From the eclipse duration to orbital period ratio, the inclination of the binary orbit is constrained to $i>70^\circ$. The most likely range for the companion mass suggests that the inclination is likely to be closer to this value than $90^\circ$. The eclipses are also consistent with earlier data, in which strong variability ('flares') and the long orbital period prevent clear detection of the period or eclipses. We also find that the bright flares occurred preferentially in the post-eclipse phase of the orbit, likely due to increased thickness at the disc-accretion stream interface preventing flares being visible during the pre-eclipse phase. This supports the notion that variable obscuration is responsible for the unusually strong variability in Swift J1858.6-0814.
Eclipsing Stellar Flare on the Demon Star Algol Binary System Observed during the MAXI-NICER Follow-up Campaign in 2018
Kyoto University（京都大学）；Chiba University（千叶大学）；RIKEN Center for Advanced Photonics (RAP)（理化学研究所先进光子学中心）；University of Colorado Boulder（科罗拉多大学博尔德分校）；National Solar Observatory（国家太阳观测台）；NASA’s Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）
Unchanged X-Ray Polarization During Accretion Dips in the Low Hard State of Cygnus X-1
Guangxi University（广西大学）；INAF Istituto di Astrofisica e Planetologia Spaziali（意大利国家天体物理研究所空间天体物理学和行星科学研究所）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）
Sub-relativistic Outflow and Hours-Timescale Large-amplitude X-ray Dips during Super-Eddington Accretion onto a Low-mass Massive Black Hole in the Tidal Disruption Event AT2022lri
Timing and Spectral Studies of the X-ray Pulsar 2S 1417$-$624 During the Outburst in 2021
我们基于中子星内部成分探测器（NICER）的观测，研究了X射线脉冲星2S 1417- 624在2021年1月最近爆发期间的时间和光谱特性。我们还使用了2018年爆发的一些早期数据来比较不同的时间和光谱特性。用Fermi/GBM研究了爆发过程中自旋周期和脉冲通量的演化，发现自旋上升速率在$\simeq(0.8-1.8)\times 10^{-11}$ Hz s $^{-1}$之间变化.脉冲轮廓显示能量依赖性和可变性。脉冲轮廓示出了随能量演变的多个峰和谷。该源的光谱状态的演变也研究了使用硬度强度图（HID）。HID显示了从水平到对角分支的过渡，这意味着源经历了从亚临界到超临界吸积状态的转变。NICER能谱由具有较高截止能量的幂律和黑体分量以及光电吸收分量的复合模型很好地描述。在NICER光谱中，在6.4 keV附近检测到铁发射线，其等效宽度为$\sim$ 0.05 keV。光子指数与临界通量以下的通量呈反相关。质量吸积率估计为$\simeq1.3\times10^{17}$ g s $^{-1}$附近的爆发的峰值。我们发现脉冲频率导数与亮度之间存在正相关关系。Ghosh和Lamb模型被应用于估计在不同的自旋上升率的磁场，这是比较早期估计的磁场在一个相对较高的质量吸积率。磁场估计为$\simeq10^{14}$ G的扭矩光度模型使用的距离估计盖亚，这是相对高于大多数其他Be/XBP。
Einstein Probe discovery of EP J171159.4-333253: an eclipsing neutron star low-mass X-ray binary with clocked bursts
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（西班牙高等科学研究理事会））；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究学院）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；INAF–Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）
