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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:65/0  |  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.
  
Phase-matching in KTP crystal for THz wave generation at room temperature and 81 K 期刊论文  OAI收割
Infrared Physics & Technology, 2019, 卷号: 97, 页码: 1-5
作者:  
C.R.Wang;  Q.K.Pan;  F.Chen;  G.Lanskii;  N.Nikolaev
  |  收藏  |  浏览/下载:34/0  |  提交时间:2020/08/24
Degradation mechanisms of optoelectric properties of GaN via highly-charged Bi-209(33+) ions irradiation 期刊论文  OAI收割
APPLIED SURFACE SCIENCE, 2018, 卷号: 440, 页码: 814-820
作者:  
Xian, Y. Q.;  Zhang, L. Q.;  Li, J. Y.;  Su, C. H.;  Chen, Y. G.
  |  收藏  |  浏览/下载:45/0  |  提交时间:2018/05/22
Preparation and Spectrum Characterization of a High Quality Linear Variable Filter 期刊论文  OAI收割
Coatings, 2018, 卷号: 8, 期号: 9, 页码: 11
作者:  
Tang, H. L.;  Gao, J. S.;  Zhang, J.;  Wang, X. Y.;  Fu, X. H.
  |  收藏  |  浏览/下载:18/0  |  提交时间:2019/09/17
New spectrum ratio properties and features for shadow detection 期刊论文  OAI收割
Pattern Recognition, 2016, 卷号: 51, 期号: 3, 页码: 85–96
作者:  
Tian JD(田建东);  Qi XJ(齐虓隽);  Qu LQ(屈靓琼);  Tang YD(唐延东)
收藏  |  浏览/下载:32/0  |  提交时间:2015/12/20
Fabrication and photoluminescence properties of Cr:YAG and Yb,Cr:YAG transparent ceramic 期刊论文  OAI收割
OPTICAL MATERIALS, 2015, 卷号: 49, 页码: 330-336
Chen, Xingtao; Lu, Tiecheng; Wei, Nian; Lu, Zhongwen; Chen, Lijia; Zhang, Qinghua; Cheng, Gang; Qi, Jianqi
收藏  |  浏览/下载:58/0  |  提交时间:2016/04/21
Synthesis and Photoluminescence of Tetravalent Cerium-Doped Alkaline-Earth-Metal Tungstate Phosphors by a Co-precipitation Method 期刊论文  OAI收割
Spectroscopy Letters, 2014, 卷号: 48, 期号: 5, 页码: 381-385
W. L.; Tao Feng, C. Y.; Wang, K.
收藏  |  浏览/下载:29/0  |  提交时间:2015/05/08
Response spectrum 0.9-2.65 m of In0.82Ga0.18As detectors by two-step growth technique (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Material Sciences and Manufacturing Technology, ICMSMT 2012, October 5, 2012 - October 6, 2012, Dalian, China
作者:  
Zhang T.
收藏  |  浏览/下载:44/0  |  提交时间:2013/03/25
InP/In0.82Ga0.18As/InP heterostructure used for infrared detector were grown on (100) S-doped InP substrates using two-step growth technique by low temperature metal-organic chemical vapor deposition. The growth was performed using TMIn  TMGa  AsH3  and PH3 as growth precursors in a horizontal reactor. The substrates on a graphite susceptor were heated by inductively coupling RF power  their temperatures were detected by a thermocouple  and the reactor pressure was kept at 10000 Pa. The growth structure of detector included In0.82Ga0.18As buffer with the thickness of 100 nm  In0.82Ga0.18As absorption layer with the thickness of 2.8 m  and the InP cap with the thickness of 0.8 m. The planar type of p-i-n detector was fabricated by Zn diffusion. The properties of In0.82Ga0.18As detector were studied  the curves of the I-V characteristics  the range of response spectrum  and the detectivity (D*) were obtained. (2013) Trans Tech Publications  Switzerland.  
Effects of alloying elements on the electronic structure and ductility of NiAl compounds investigated by X-ray absorption fine structure 期刊论文  OAI收割
Philosophical Magazine, 2013, 卷号: 93, 期号: 17, 页码: 2161-2171
J. S. Tian; G. M. Han; H. Wei; Q. Zheng; T. Jin; X. F. Sun; Z. Q. Hu
收藏  |  浏览/下载:30/0  |  提交时间:2013/12/24
Observational constraints on cosmic neutrinos and dark energy revisited 期刊论文  OAI收割
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2012, 期号: 11
作者:  
Wang, Xin;  Meng, Xiao-Lei;  Zhang, Tong-Jie;  Shan, HuanYuan;  Gong, Yan
收藏  |  浏览/下载:91/0  |  提交时间:2016/11/21