Accretion-powered pulsations in an apparently quiescent neutron star binary
Anne M. Archibald, Slavko Bogdanov, Alessandro Patruno, Jason W. T. Hessels, Adam T. Deller, Cees Bassa, Gemma H. Janssen, Vicky M. Kaspi, Andrew G. Lyne, Ben W… 展开作者
Anne M. Archibald, Slavko Bogdanov, Alessandro Patruno, Jason W. T. Hessels, Adam T. Deller, Cees Bassa, Gemma H. Janssen, Vicky M. Kaspi, Andrew G. Lyne, Ben W. Stappers, Shriharsh P. Tendulkar, Caroline R. D'Angelo, Rudy Wijnands
吸积毫秒X射线双星是低质量X射线双星的一个重要子集，在偶然的明亮爆发期间可以观察到相干X射线脉动（X射线光度$L_X\sim 10^{36}$ erg s $^{-1}$）。这些脉动表明物质正被引导到中子星的磁极上。然而，这样的源花费大部分时间在低光度，静止状态（$L_X\lesssim 10^{34}$ erg s $^{-1}$），其中吸积流到中子星（如果有的话）的性质还没有得到很好的理解。在这里，我们报告说，毫秒脉冲星/低质量X射线二进制过渡对象PSR J1023+0038间歇性地显示相干X射线脉动的光度比任何其他吸积毫秒X射线脉冲星中观察到的微弱近100倍。我们的结论是，尽管它的低光度PSR J 1023 +0038的经验集通道吸积，一个发现，挑战现有的模型吸积到磁化中子星。
英文摘要：
Accreting millisecond X-ray pulsars are an important subset of low-mass X-ray binaries in which coherent X-ray pulsations can be observed during occasional, bright outbursts (X-ray luminosity $L_X\sim 10^{36}$ erg s$^{-1}$). These pulsations show that matter is being channeled onto the neutron star's magnetic poles. However, such sources spend most of their time in a low-luminosity, quiescent state ($L_X\lesssim 10^{34}$ erg s$^{-1}$), where the nature of the accretion flow onto the neutron star (if any) is not well understood. Here we report that the millisecond pulsar/low-mass X-ray binary transition object PSR J1023+0038 intermittently shows coherent X-ray pulsations at luminosities nearly 100 times fainter than observed in any other accreting millisecond X-ray pulsar. We conclude that in spite of its low luminosity PSR J1023+0038 experiences episodes of channeled accretion, a discovery that challenges existing models for accretion onto magnetized neutron stars.
IGR J06074+2205 is a poorly studied X-ray source with a Be star companion. It has been proposed to belong to the group of Be/X-ray binaries. In Be/X-ray binaries, accretion onto the neutron star occurs via the transfer of material from the Be star's circumstellar disk. Thus, in the absence of the disk, no X-ray should be detected. The main goal of this work is to study the quiescent X-ray emission of IGR J06074+2205 during a disk-loss episode. We show that at the time of the XMM-Newton observation the decretion disk around the Be star had vanished. Still, accretion appears as the source of ene…
We report on the Neutron Star Interior Composition Explorer (NICER) monitoring campaign of the 468 Hz accreting millisecond X-ray pulsar IGR J17379-3747. From a detailed spectral and timing analysis of the coherent pulsations we find that they show a strong energy dependence, with soft thermal emission lagging about 640 microseconds behind the hard, Comptonized emission. Additionally, we observe uncommonly large pulse fractions, with measured amplitudes in excess of 20% sinusoidal fractional amplitude across the NICER passband and fluctuations of up to ~70%. Based on a phase-resolved spectral …
We report a 72 ks XMM-Newton observation of the Be/X-ray pulsar (BeXRP) RX J0812.4-3114 in quiescence ($L_X \approx 1.6 \times 10^{33}~\mathrm{erg~s^{-1}}$). Intriguingly, we find a two component spectrum, with a hard power-law ($Γ\approx 1.5$) and a soft blackbody-like excess below $\approx 1~\mathrm{keV}$. The blackbody component is consistent in $kT$ with a prior quiescent Chandra observation reported by Tsygankov et al. and has an inferred blackbody radius of $\approx 10~\mathrm{km}$, consistent with emission from the entire neutron star (NS) surface. There is also mild evidence for an abs…
A FAST search for radio pulsations during the dormant state of the AMSPs IGR J00291+5934 and MAXI J1957+032
Institute of Space Sciences (ICE, CSIC)（空间科学研究所）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚太空研究学院）；Universidad de Santiago de Chile (USACH)（智利圣地亚哥大学）；Center for Interdisciplinary Research in Astrophysics and Space Sciences (CIRAS)（天体物理学与空间科学跨学科研究中心）；INAF/IASF Palermo（意大利国家天体物理研究所巴勒莫天文台）；Université Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学）；INAF–Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；INAF Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Università degli Studi di Cagliari（卡利亚里大学）
Detection of low-luminosity X-ray pulsations from the accreting millisecond pulsar IGR J17511-3057: An ever-thinning thread between bright accretion and sub-luminous states
INAF–Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；INAF-Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（加泰罗尼亚高等研究理事会））；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究院）；INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica（意大利国家天体物理研究所空间天体物理与宇宙学研究所）；ASI - Agenzia Spaziale Italiana（意大利航天局）
X-ray and radio observations of the AMXP MAXI J1957+032 covering the 2022-2025 outbursts
Qingdao University of Technology（青岛理工大学）；SRON - Space Research Organisation Netherlands（荷兰空间研究所）；Peking University（北京大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Nanjing Normal University（南京师范大学）；Xiangtan University（湘潭大学）
Cepheids are pulsating variable stars with a periodic chromospheric response at UV wavelengths close to their minimum radius phase. Recently, an X-ray variable signature was captured in observations during the \emph{maximum} radius phase. This X-ray emission came as a surprise and is not understood. In this work, we use the modern astrophysical code, PLUTO, to investigate the effects of pulsations on Cepheid X-ray emission. We run a number of hydrodynamic numerical simulations with a variety of initial and boundary conditions in order to explore the capability of shocks to produce the observed…
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Detection of a large Be circumstellar disk during X-ray quiescence of XTE J1946+274
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