Nonlinear Variability Observed with Insight-HXMT in MAXI J1820+070 and MAXI J1535-571  

作　　者：Qi Ding Long Ji Qing-Cui Bu Tiekuang Dong Jin Chang 

机构地区：[1]Key Laboratory of Dark Matter and Space Astronomy,Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210033,China [2]School of Astronomy and Space Sciences,University of Science and Technology of China,Hefei 230026,China [3]School of Physics and Astronomy,Sun Yat-sen University,Zhuhai 519000,China [4]Institut für Astronomie und Astrophysik,Kepler Center for Astro and Particle Physics,Eberhard Karls,Universität,Sand 1,D-72076 Tübingen,Germany [5]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Research in Astronomy and Astrophysics》2023年第8期346-354,共9页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC,grant Nos.12173103 and U1738205);supported by the China Scholarship Council under No.202104910250;based on observations with Insight-HXMT,a project funded by the China National Space Administration(CNSA)and the Chinese Academy of Sciences(CAS)。

摘　　要：We present the timing analysis of the nonlinear variability in two black hole low mass X-ray binaries MAXI J1820+070 and MAXI J1535-571 by using the bicoherence,a measure of phase coupling at different Fourier frequencies.We found different patterns,e.g.,“cross”and“hypotenuse,”for LFQPOs in different outburst states.When they can be clearly distinguished,bicoherence patterns are similar over a wide energy range of 1–100 keV.It is intriguing that in some type-C QPOs we found the patterns that are normally observed in type-B QPOs.On the contrary,the“hypotenuse”pattern,a characteristic of type-C QPOs,was detected in a type-B QPO.This suggests that different types of QPOs may originate from similar underlying mechanisms.In addition,we speculate that the nonlinear variability may be a promising approach to disentangle distinct QPO models which assume different interactions between the broadband noise and QPO components.

关 键 词：black hole physics-instrumentation detectors-methods data analysis-X-rays BINARIES 

分 类 号：P145.8[天文地球—天体物理]