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Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei 期刊论文  OAI收割
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2020, 卷号: 493, 期号: 1, 页码: 1500-1511
作者:  Shankar, Francesco;  Weinberg, David H.;  Marsden, Christopher;  Grylls, Philip J.;  Bernardi, Mariangela
  |  收藏  |  浏览/下载：23/0  |  提交时间：2021/12/06
Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT 期刊论文  OAI收割
Astrophysics and Space Science, 2020, 卷号: 365, 页码: 158
作者:  HXMT
  |  收藏  |  浏览/下载：49/0  |  提交时间：2022/02/08
Insight-HXMT  Geant4 simulation  Background observation  Astrophysics  - Instrumentation and Methods for Astrophysics  Abstract: Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, in-orbit backgrounds of these three telescopes had been estimated through Geant4 simulation, in order to investigate the instrument performance and the achievement of scientific goals. In this work, these simulated backgrounds are compared with in-orbit observations. Good agreements are shown for all three telescopes. For HE, (1) the deviation of the simulated background rate after two years of operation in space is 5 % from the observation  (2) the total background spectrum and the relative abundance of the 67 keV line show long-term increases both in simulations and observations. For ME, (1) the deviation of simulated background rate is within 15 % from the observation, and (2) there are no obvious long-term increase features in the background spectra of simulations and observations. For LE, the background level given by simulations is also consistent with observations. The consistencies of these comparisons validate that the Insight-HXMT mass model, i.e., space environment components and models adopted, physics processes selected, and detector constructions built, is reasonable. However, the line features at 7.5 and 8.0 keV, which are obvious in the observed spectra of LE, are not evident in simulations. This might result from uncertainties in the LE constructions.  
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.  
Black holes, gravitational waves and fundamental physics: a roadmap 期刊论文  OAI收割
CLASSICAL AND QUANTUM GRAVITY, 2019, 卷号: 36, 期号: 14, 页码: 178
作者:  Barack, Leor;  Cardoso, Vitor;  Nissanke, Samaya;  Sotiriou, Thomas P.;  Askar, Abbas
  |  收藏  |  浏览/下载：190/0  |  提交时间：2019/09/26
Black holes, gravitational waves and fundamental physics: a roadmap 期刊论文  OAI收割
CLASSICAL AND QUANTUM GRAVITY, 2019, 卷号: 36, 期号: 14, 页码: 178
作者:  
  |  收藏  |  浏览/下载：123/0  |  提交时间：2019/10/28
Advances of Microgravity Sciences 期刊论文  OAI收割
空间科学学报, 2014, 卷号: 34, 期号: 5, 页码: 733-739
作者:  Kang Q(康琦);  Long M(龙勉);  ZhangYZ;  Duan L(段俐);  Zhao JF(赵建福)
收藏  |  浏览/下载：31/0  |  提交时间：2015/09/02
Numerical simulation of time delay interferometry for a LISA-like mission with the simplification of having only one interferometer 期刊论文  OAI收割
ADVANCES IN SPACE RESEARCH, 2013, 卷号: 51, 期号: 1, 页码: 198-206
作者:  Dhurandhar, S. V.;  Ni, W. -T.;  Wang, G.
收藏  |  浏览/下载：22/0  |  提交时间：2014/01/08
GAUGE: the GrAnd Unification and Gravity Explorer 期刊论文  OAI收割
EXPERIMENTAL ASTRONOMY, 2009, 卷号: 23, 期号: 2, 页码: 549-572
作者:  Amelino-Camelia, G.;  Aplin, K.;  Arndt, M.;  Barrow, J. D.;  Bingham, R. J.
收藏  |  浏览/下载：46/0  |  提交时间：2011/12/08
ASTROD and ASTROD I - Overview and progress 期刊论文  OAI收割
INTERNATIONAL JOURNAL OF MODERN PHYSICS D, 2008, 卷号: 17, 期号: 7, 页码: 921-940
作者:  Ni, Wei-Tou
收藏  |  浏览/下载：26/0  |  提交时间：2011/12/29
AGN black hole masses and methods to estimate the mass 期刊论文  OAI收割
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 2005, 卷号: 57, 期号: 1, 页码: 183-186
作者:  Xie GZ(谢光中);  Chen LE(陈洛恩);  Xie, ZH;  Ma L(马力);  Zhou SB(周曙白)
收藏  |  浏览/下载：11/0  |  提交时间：2016/04/12