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The Year-scale X-Ray Variations in the Core of M87

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Research in Astronomy and Astrophysics 2023年第6期23卷 203-211页

作者： Yu-lin cheng Fei Xiang Heng Yu Shu-Mei Jia Xiang-Hua li cheng-kui li Yong Chen Wen-cheng Feng Department of Astronomy Yunnan UniversityKunming 650091China Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China

The analysis of light variation of M87 can help us understand the disk *** the past decade,M87 has experienced several short-term light variabilities related to *** also find that there are year-scale X-ray variations in the core of *** light variability properties are similar to *** re-analyzing 56Chandra observations from 2007 to 2019,we distinguish the“non-flaring state”from“flaring state”in the light *** removing flaring state data,we identify four gas clumps in the nucleus and all of them can be well fitted by the clumpy-ADAF *** average mass accretion rate is~0.16M⊙yr^(-1).We analyze the photon index(Γ)-flux(2-10 keV)correlation between the non-flaring state and flaring *** the non-flaring states,the flux is inversely proportional to the photon *** the flaring states,we find no obvious correlation between the two *** addition,we find that the flare always occurs at a high mass accretion rate,and after the luminosity of the flare reaches the peak,it will be accompanied by a sudden decrease in *** results can be explained as that the energy released by magnetic reconnection destroys the structure of the accretion disk,thus the luminosity decreases rapidly and returns to normal levels thereafter.

关键词： X-rays:galaxies galaxies:clusters:individual(M87) accretion accretion disks

The YSZ,Planck - YSZ,XMM scaling relation and its difference between cool-core and non-cool-core clusters

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Research in Astronomy and Astrophysics 2019年第7期19卷 151-162页

作者： Yue Zhu Yuan-Hao Wang Hai-Hui Zhao Shu-Mei Jia cheng-kui li Yong Chen Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China

We construct a sample of 70 clusters using data from XMM-Newton and Planck to investigate the YSZ,Planck-YSZ,XMM scaling relation and the cool-core influences on this ***,XMM is calculated by accurately de-projected temperature and electron number density profiles derived from ***,Planckis the latest Planck data restricted to our precise X-ray cluster size θ*** study the cool-core influences on the YSZ,Planck-YSZ,XMM scaling relation,we apply two criteria,namely the limits of central cooling time and classic mass deposition rate,to distinguish cool-core clusters(CCCs) from non-cool-core clusters(NCCCs).We also use YSZ,Planckfrom other papers,which are derived from different methods,to confirm our *** intercept and slope of the YSZ,Planck-YSZ,XMM scaling relation are A =-0.86 ± 0.30 and B = 0.83 ± 0.06 *** intrinsic scatter is σins= 0.14 ± *** ratio of YSZ,Planck/YSZ,XMM is 1.03 ± 0.05,which is in excellent statistical agreement with *** in the YSZ,Planck-YSZ,XMM scaling relation between CCCs and NCCCs are found in the *** are independent of the cool-core classification criteria and YSZ,Planckcalculation methods,although the discrepancies are more significant under the classification criteria of classic mass deposition *** intrinsic scatter of CCCs(0.04) is quite small compared to that of NCCCs(0.27).The ratio of YSZ,Planck/YSZ,XMM for CCCs is 0.89 ± 0.05,suggesting that CCCs’ YSZ,XMM may overestimate the Sunyaev-Zel’dovich(SZ)*** contrast,the ratio of YSZ,Planck/YSZ,XMM for NCCCs is 1.14 ± 0.12,which indicates that NCCCs’ YSZ,XMM may underestimate the SZ signal.

关键词： galaxies:clusters:intracluster medium X-rays:galaxies:clusters cosmology:observations

Weak Merging Scenario of CLASH Cluster A209

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Research in Astronomy and Astrophysics 2024年第4期24卷 174-182页

作者： Wen-cheng Feng Heng Yu Hai-Hui Zhao Xiao-Lan Hou Shu-Mei Jia cheng-kui li Yu-lin cheng Paolo Tozzi Ming Sun Yong Chen Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Astronomy Yunnan UniversityKunming 650091China INAF—Osservatorio Astrofisico di Arcetri Largo E.Fermi50122 FirenzeItaly Department of Astronomy University of VirginiaP.O.Box 400325CharlottesvilleVA 22904-4325USA

We study the structural and dynamical properties of A209 based on Chandra and XMM-Newton *** obtain detailed temperature,pressure,and entropy maps with the contour binning method,and find a hot region in the NW *** X-ray brightness residual map and corresponding temperature profiles reveal a possible shock front in the NW direction and a cold front feature in the SE *** with the galaxy luminosity density map we propose a weak merger scenario.A young sub-cluster passing from the SE to NW direction could explain the optical subpeak,the intracluster medium temperature map,the X-ray surface brightness excess,and the X-ray peak offset together.

关键词： X rays:galaxies:clusters galaxies:clusters:intracluster medium galaxies:clusters:Abell 209

Analysis of Bright Source Hardness Ratios in the 4 yr Insight-HXMT Galactic Plane Scanning Survey Catalog

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Research in Astronomy and Astrophysics 2024年第2期24卷 154-170页

作者： Chen Wang Jin-Yuan liao Ju Guan Yuan liu cheng-kui li Na Sai Jing Jin Shuang-Nan Zhang Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy School of Physics and TechnologyWuhan UniversityWuhan 430072China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhan 430072China

We conduct a statistical analysis of the hardness ratio(HR)for bright sources in the 4 yr Galactic Plane Scanning Survey catalog of *** on the stable(variable)flux F_(s)(F_(v))or spectrum S_(s)(S_(v))of each source,the bright sources are classified into three groups:F_(v)&S_(v),F_(v)&S_(s),and F_(s)&_(s).Our study of the HR characteristics in different types of sources reveals that accretion-powered neutron star(NS)low-mass X-ray binaries(LMXBs)exhibit softer energy spectra than NS high-mass X-ray binaries(HMXBs),but harder energy spectra than black hole binaries in most *** difference is probably due to their different magnetic field ***,Fv&Sv LMXBs tend to be harder than Fv&Ss LMXBs below 7 keV,while the opposite is true for *** results suggest that LMXBs may dominate unclassified sources,and NS binaries are likely to be the primary type of X-ray binaries with ambiguous compact *** comparing the HR of transient sources in their outburst and low-flux states,it is found that the averaged HR of four sources in the two states are roughly comparable within *** also investigate the spatial properties of the three groups and find that Fv&Sv sources are mainly located in the longitude of-20°

关键词： catalogs-surveys-methods data analysis-X-rays general

The performance of out-of-time events of the follow-up X-ray telescope onboard Einstein probe

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Radiation Detection Technology and Methods 2024年第2期8卷 1148-1154页

作者： Hai-Sheng Zhao Juan Zhang Ju Guan cheng-kui li Shu-Mei Jia li-Ming Song Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadBeijing100049People’s Republic of China

Purpose:The purpose of this study is to investigate the performance of out-of-time events(OoT events)in the Follow-up X-ray Telescope(FXT)onboard the Einstein *** OoT events,registered on the PN-CCD during its readout time,can provide information on the sources,e.g.,spectral indices,and diagnose the behavior of ***:In order to analyze the characteristics of OoT events,we simulated sources,each of which had been modeled using an absorbed power law combined with Gaussians,in different FXT modes and different *** allowed us to determine the OoT spectral indices and pile-up ***:In the timing mode of FXT,the OoT events occupy a large proportion and the OoT correction must be done with the assumption that all photons originate from the source position on the *** for some bright sources,the OoT events may be sufficient to derivate the source spectra,especially when pile-up occurs,particularly in the full frame mode and the partial window mode of ***:We conclude that the OoT events can provide additional information about the celestial sources and can be used to estimate whether the pile-up occurs or not and the scope of ***,they can be also used to determine the new sources and improve the detection significance of a source.

关键词： Out-of-time Event PN-CCD Pile-up

Statistical Properties of X-Ray Bursts from SGR J1935+2154 Detected by Insight-HXMT

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Research in Astronomy and Astrophysics 2023年第11期23卷 112-117页

作者： Wen-Long Zhang Xiu-Juan li Yu-Peng Yang Shuang-Xi Yi cheng-kui li Qing-Wen Tang Ying Qin Fa-Yin Wang School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China School of Cyber Science and Engineering Qufu Normal UniversityQufu 273165China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Physics School of Physics and Materials ScienceNanchang UniversityNanchang 330031China Department of Physics Anhui Normal UniversityWuhu 241000China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China

As one class of the most important objects in the universe,magnetars can produce a lot of different frequency bursts including X-ray *** Cai et al.,75 X-ray bursts produced by magnetar SGR J1935+2154 during an active period in 2020 are published,including the duration and net photon counts of each burst,and waiting time based on the trigger time *** this paper,we utilize the power-law model,dN(x)/dx∝(x+x_0)~((-α)_x),to fit the cumulative distributions of these *** can be found that all the cumulative distributions can be well fitted,which can be interpreted by a self-organizing criticality ***,we check whether this phenomenon still exists in different energy bands and find that there is no obvious *** findings further confirm that the X-ray bursts from magnetars are likely to be generated by some self-organizing critical process,which can be explained by a possible magnetic reconnection scenario in magnetars.

关键词： stars:magnetars X-rays:bursts magnetic reconnection

Localization Method for the Pointing Observation with the Collimated Telescopes of Insight-HXMT

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Research in Astronomy and Astrophysics 2023年第5期23卷 38-43页

作者： Qi Luo Jin-Yuan liao Yi Nang cheng-kui li Chen Wang Na Sai Ju Guan Yu-Peng Chen cheng-cheng Guo Yuan liu Shu Zhang Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Physics and Technology Wuhan UniversityWuhan 430072China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhan 430072China

An accurate target source position is sometimes useful for the pointing observation with the collimated telescopes of the Hard X-ray Modulation Telescope(Insight-HXMT),which is determined by the reliability of the instrumental ***-HXMT has the unique design that all three main payloads(LE,ME and HE)consist of detector groups with three fields of views(FOVs)whose orientations differ by 60°.As the point-spread functions are different at different positions in the FOV coordinates,the count rate ratios between the detector groups depend on the position of an X-ray source in the *** on the multi-FOV design,we develop a localization method for an X-ray source in the pointing observation of *** accuracy of the method is investigated with the pointing observations of the Crab with different *** find that the statistical error decreases with the exposure,and the systematic error is dominant for the exposure>128 *** the exposure of1024 s,the total error is 0°.015 for the *** method can effectively distinguish the Rapid Burster H 1730–333and Slow Burster GX 354–0,which are only 0°.5 apart and can both contribute to bursts in the light curve obtained by *** also apply the pointing observation localization method to locate the X-ray counterpart of FRB 200428 with high *** located position is consistent with SGR J1935+2154 within 1σuncertainty of 10′,which provides important evidence that fast radio bursts can originate from magnetars.

关键词： instrumentation detectors-space vehicles instruments-telescopes

Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGR J1935+2154 Based on Insight-HXMT

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Research in Astronomy and Astrophysics 2024年第6期24卷 225-233页

作者： Xue-Feng Lu li-Ming Song Ming-Yu Ge Shuang-Nan Zhang Jin-Lu Qu Ce Cai Cong-Zhan liu cheng-kui li Yu-Cong Fu Ying-Chen Xu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In October 2022,the magnetar SGR J1935+2154 entered the active outburst *** the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 *** than 300 bursts were detected,and a certain amount of persistent radiation signals were also *** paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT *** the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are *** found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+*** observed zero-lag burst does not have a unique *** time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the *** also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： radiation mechanisms:general dense matter magnetic fields

An X-Ray Burst Associated with FRB 200428 from a Magnetar-asteroid Impact

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Research in Astronomy and Astrophysics 2023年第8期23卷 238-246页

作者： Ze-Nan liu Yuan-Pei Yang Wei-Yang Wang Zhao Joseph Zhang Qiao-Chu li Ken Chen Jia Ren Bin-Bin Zhang cheng-kui li Shuang-Nan Zhang Zi-Gao Dai School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210023China South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy School of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China

Fast radio bursts(FRBs)are extragalactic radio transients with millisecond duration and brightness *** FRB-associated X-ray burst(XRB)was recently found to arise from the Galactic magnetar SGR J1935+*** the model of Dai,in which an FRB may originate from a magnetar encountering an asteroid,we focus on explaining the spectrum of the XRB associated with FRB 200428 from SGR J1935+*** between asteroidal fragments and the magnetar surface produce a fireball,which further expands *** to the velocity difference among some shells in the fireball,internal shocks would form far away from the magnetar,and further emit X-ray *** propose that the FRB-associated XRB can be produced by synchrotron emission from the internal shocks,and then constrain the physical parameters by the observed XRB spectrum.

关键词： stars magnetars-minor planets-asteroids general-radiation mechanisms general