中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共7条，第1-7条

帮助

条数/页：排序方式：
	Timing properties of the X-ray accreting pulsar RX J0440.9+4431 studied with Insight-HXMT and NICER 期刊论文 OAI收割 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2023, 卷号: 526, 期号: 3, 页码: 3637-3651 作者: Li, P P; Tao, L; Tuo, Y L; Ge, M Y; Kong, L D \| 收藏 \| 浏览/下载：20/0 \| 提交时间：2024/03/29 accretion, accretion disc X-rays: binaries stars: neutro pulsars: individual (RX J0440.9+4431)
	Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity 期刊论文 OAI收割 Monthly Notices of the Royal Astronomical Society, 2020, 卷号: 497, 页码: 5498-5506 作者: HXMT \| 收藏 \| 浏览/下载：44/0 \| 提交时间：2022/02/08 stars: neutron pulsars: individual: Swift J0243.6+6124 X-rays: binaries Astrophysics - High Energy Astrophysical Phenomena Abstract: Based on Insight-HXMT data, we report on the pulse fraction evolution during the 2017-2018 outburst of the newly discovered first Galactic ultraluminous X-ray (ULX) source Swift J0243.6+6124. The pulse fractions of 19 observation pairs selected in the rising and fading phases with similar luminosity are investigated. The results show a general trend of the pulse fraction increasing with luminosity and energy at supercritical luminosity. However, the relative strength of the pulsation between each pair evolves strongly with luminosity. The pulse fraction in the rising phase is larger at luminosity below 7.71 × 10³⁸ erg s^-1, but smaller at above. A transition luminosity is found to be energy independent. Such a phenomenon is first confirmed by Insight-HXMT observations and we speculate that it may have relation with the radiation-pressure-dominated accretion disc.
	An underlying clock in the extreme flip-flop state transitions of the black hole transient Swift J1658.2-4242 期刊论文 OAI收割 Astronomy and Astrophysics, 2020, 卷号: 641, 页码: A101 作者: HXMT \| 收藏 \| 浏览/下载：58/0 \| 提交时间：2022/02/08 accretion accretion disks black hole physics X-rays: binaries time Astrophysics - High Energy Astrophysical Phenomena Abstract: Aims: Flip-flops are top-hat-like X-ray flux variations, which have been observed in some transient accreting black hole binary systems, and feature simultaneous changes in the spectral hardness and the power density spectrum (PDS). They occur at a crucial time in the evolution of these systems, when the accretion disc emission starts to dominate over coronal emission. Flip-flops remain a poorly understood phenomenon, so we aim to thoroughly investigate them in a system featuring several such transitions. Methods: Within the multitude of observations of Swift J1658.2-4242 during its outburst in early 2018, we detected 15 flip-flops, enabling a detailed analysis of their individual properties and the differences between them. We present observations by XMM-Newton, NuSTAR, Astrosat, Swift, Insight-HXMT, INTEGRAL, and ATCA. We analysed their light curves, searched for periodicities, computed their PDSs, and fitted their X-ray spectra, to investigate the source behaviour during flip-flop transitions and how the interval featuring flip-flops differs from the rest of the outburst. Results: The flip-flops of Swift J1658.2-4242 are of an extreme variety, exhibiting flux differences of up to 77% within 100 s, which is much larger than what has been seen previously. We observed radical changes in the PDS simultaneous with the sharp flux variations, featuring transitions between the quasi-periodic oscillation types C and A, which have never been observed before. Changes in the PDS are delayed, but more rapid than changes in the light curve. Flip-flops occur in two intervals within the outburst, separated by about two weeks in which these phenomena were not seen. Transitions between the two flip-flop states occurred at random integer multiples of a fundamental period of 2.761 ks in the first interval and 2.61 ks in the second. Spectral analysis reveals the high and low flux flip-flop states to be very similar, but distinct from intervals lacking flip-flops. A change of the inner temperature of the accretion disc is responsible for most of the flux difference in the flip-flops. We also highlight the importance of correcting for the influence of the dust scattering halo on the X-ray spectra.
	Study of the X-ray properties of the neutron star binary 4U 1728-34 from the soft-to-hard state 期刊论文 OAI收割 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2019, 卷号: 484, 期号: 3, 页码: 3004-3016 作者: Wang, Yanan; Mendez, Mariano; Altamirano, Diego; Zhang, Guobao; Belloni, T. M. \| 收藏 \| 浏览/下载：127/0 \| 提交时间：2019/04/22 accretion, accretion disc X-rays: individual: 4U 1728-34
	General relativistic magnetohydrodynamic and Monte Carlo Modeling of sagittarius A 期刊论文 OAI收割 Astrophys Space Sci, 2011, 卷号: 336, 页码: 145-149 Guy Hilburn; Edison Liang; Siming Liu; Hui Li 收藏 \| 浏览/下载：12/0 \| 提交时间：2012/08/07 Accretion disc Black hole Galactic Center Magnetohydrodynamics
	The variability of BL Lac 3C 66A 期刊论文 OAI收割 CHINESE PHYSICS, 2004, 卷号: 13, 期号: 8, 页码: 1375-1376 作者: Su CY(苏成悦) 收藏 \| 浏览/下载：28/0 \| 提交时间：2016/04/12 active galactic nuclei black hole accretion disc variability
	Optically-thick accretion discs with advection 期刊论文 OAI收割 CHINESE PHYSICS, 2002, 卷号: 11, 期号: 12, 页码: 1319-1323 作者: Chen, LH; Wu M(吴枚); Wu, M; Shang, RC 收藏 \| 浏览/下载：17/0 \| 提交时间：2016/06/29 accretion disc black hole physics SSD ADAF