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X-ray Spectroscopy of Dips of Cir X-1

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Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 693-704页

作者： Ya-Juan Lei fang-jun lu Jin-lu Qu Li-Ming Song Cheng-Min Zhang Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We present X-ray spectral analyses of the low-mass X-ray binary Cir X-1 during X-ray dips, using the Rossi X-ray Timing Explorer （RXTE） data. Each dip was divided into several segments, and the spectrum of each segment was fitted with a three-component blackbody model, in which the first two components are affected by partial covering and the third one is unaffected. A Gaussian emission line is also included in the spectral model to represent the Fe Kα line at - 6.4 keV. The fitted temperatures of the two partially covered components are about 2 keV and 1 keV, while the uncovered component has a temperature of -0.5-0.6 keV. The equivalent blackbody emission radius of the hottest component is the smallest and that of the coolest component is the largest. During the dips the fluxes of the two hot components are linearly correlated, while that of the third component does not show any significant variation. The Fe line flux remains constant, within the errors, during the short dips. However, during the long dips the line flux varies significantly and is positively correlated with the fluxes of the two hot components. These results suggest; （1） that the temperature of the X-ray emitting region decreases with radius, （2） that the Fe Kα line emitting region is close to the hot continuum emitting region, and （3） that the size of the Fe line emitting region is larger than that of the obscuring matter causing the short dips but smaller than the region of that causing the long dips.

关键词： stars individual (Circinus X-1) -- stars neutron -- X-rays stars

High spatial resolution spectroscopy of G292.0+1.8 with Chandra

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Research in Astronomy and Astrophysics 2014年第10期14卷 1279-1288页

作者： Xue-Juan Yang Xiao-Qin Liu Shun-Yu Li fang-jun lu Faculty of Materials Optoelectronics and PhysicsXiangtan University Particle Astrophysics Center Institute of High Energy PhysicsChinese Academy of Sciences

We present high spatial resolution X-ray spectroscopy of supernova rem- nant G292.0＋1.8 made with Chandra observations. The X-ray emitting region of this remnant was divided into 25 × 25 pixels with a scale of 20＂ × 20＂ each. Spectra of 328 pixels were created and fitted with an absorbed one component non-equilibrium ionization model. With the spectral analysis results, we obtained maps of absorbing column density, temperature, ionization age and abundances for O, Ne, Mg, Si, S and Fe. The abundances of O, Ne and Mg show tight correlations between each other in the range of about two orders of magnitude, suggesting that they are all from explo- sive C/Ne burning. Meanwhile, the abundances of Si and S are also well correlated, indicating that they are the ashes of explosive O-burning or incomplete Si-burning. The Fe emission lines are not prominent in the whole remnant, and their abundance is significantly reduced, indicating that the reverse shock may not have propagated to the Fe-rich ejecta. Based on relative abundances of O, Ne, Mg, Si and Fe to Si, we suggest a progenitor mass of 25 - 30 M⊙ for this remnant.

关键词： ISM supernova remnants -- ISM individual G292.0+1.8

XMM-Newton observation of the eclipsing binary Algol

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Research in Astronomy and Astrophysics 2011年第4期11卷 457-470页

作者： Xue-Juan Yang fang-jun lu Bemd Aschenbach Li Chen Faculty of Materials Optoelectronics and Physics Xiangtan University Xiangtan 411105China Particle Astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Max-Planck-Institut fur Extraterrestrische Physik 85741 Garching Germany Department of Astronomy Beijing Normal University Beijing 100875 China

We present an XMM-Newton observation of the eclipsing binary Algol which contains an X-ray dark B8V primary and an X-ray bright K2IV secondary. The observation covered the optical secondary eclipse and captured an X-ray flare that was eclipsed by the B star. The XMM-Newton European Photon Imaging Camera and Reflection Grating Spectrometer spectra of Algol in its quiescent state are described by a two-temperature plasma model. The cool component has a temperature around 6.4× 106 K while that of the hot component ranges from 2 to 4.0× 107 K. Coronal abundances of C, N, O, Ne, Mg, Si and Fe were obtained for each component for both the quiescent and the flare phases, generally with upper limits for S and Ar, and upper limits for C, N, and O from the hot component. F-tests show that the abundances do not need to be different between the cool and the hot component and between the quiescent and the flare phase with the exception of Fe. Although the Fe abundance of the cool component remains constant at -0.14, the hot component shows an Fe abundance of -0.28, which increases to -0.44 during the flare. This increase is expected from the chromospheric evaporation model. The absorbing column density NH of the quiescent emission is 2.5 - 1020 cm-2, while that of the flare-only emission is significantly lower and consistent with the column density of the interstellar medium. This observation substantiates earlier suggestions of the presence of X-ray absorbing material in the Algol system.

关键词： stars abundance -- star binaries eclipsing -- stars flare -- stars indi-vidual Algol

In-orbit performance of HE onboard Insight-HXMT in the first 5 years

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Radiation Detection Technology and Methods 2023年第1期7卷 3-14页

作者： Xu-fang Li Cong-Zhan Liu Yi-Fei Zhang Xiao-Bo Li Zheng-Wei Li Xue-Feng lu Zhi Chang Ming-Yu Ge Juan Zhang Yu-Peng Xu fang-jun lu Li-Ming Song Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Science19B Yuquan RoadShijingshan DistrictBeijing 100049China

Purpose The high-energy X-ray telescope(HE),one of the three main payloads of the Insight-HXMT mission,is composed of eighteen NaI(Tl)/CsI(Na)phoswich detectors,where NaI(Tl)serves as the primary detector covering 20–250 keV,and CsI(Na)is used as an active shield detector to suppress the background of NaI(Tl)and also serves as an all-sky gammaray burst monitor covering 0.2–*** this paper,we review the in-orbit performance of HE in the first 5 years since Insight-HXMT was launched on june 15,*** The major performances we concern include the gain and energy resolution of NaI(Tl)and CsI(Na)detectors,the performance of pulse shape discriminator(PSD)and system dead *** this work,we investigate these performances mainly using the data of blank-sky observations and the data when the telescope is in earth *** The overall performance of HE/NaI(Tl)is very stable in the first 5 years,whereas the gain of HE/CsI(Na)shows a continuously increasing trend and should be calibrated *** In general,HE is still in good health and well-calibrated status after five-year’s *** in-orbit performance of HE has no significant deviation from *** is expected to be in operation healthily for another several years of extended mission life.

关键词： Insight-HXMT Hard X-ray telescope Scintillation detector In-orbit

Relationship of plasma creatinine and lactic acid in type 2 diabetic patients without renal dysfunction

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Chinese Medical Journal 2009年第21期122卷 2547-2553页

作者： LIU fang lu jun-xi TANG jun-ling LI Li lu Hui-juan HOU Xu-hong JIA Wei-ping XIANG Kun-san Department of Endocrinology and Metabolism Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai Institute for Diabetes Shanghai Clinical Center of Diabetes Shanghai 200233 China

Background As one of most widely-used biguanides, metformin can induce the lactic acidosis in patients with renal failure though its incidence is very low. However, lactic acidemia induced by metformin was reported in patients without renal dysfunction. It is unclear that whether lactatemia exists in diabetic patients with normal renal function in Chinese or not and its influencing factors. This study aimed to clarify the influencing factors of lactic acid, and identify a practiced clinical marker to predict the hyperlactacidemia in diabetics with normal renal function. Methods The clinical data and venous blood samples of 1024 type 2 diabetic patients treated with （n=426） or without metformin （n=599） were collected. The lactic acid was assayed by enzyme-electrode method. The biochemical indexes included creatinine （Cr） and hepatase were measured with enzymatic procedures. The lactic acid concentrations of different Cr subgroups were compared, and the correlation and receiver operating characteristic curve analysis were used. Results The mean lactic acid level and the proportion of hyperlactatemia of metformin group were significantly higher than that of non-metformin group （P 〈0.01）, but no lactic acidosis was found in all patients. The correlation and multiple stepwise regression analysis indicated that the correlative factors of lactic acid in turn were Cr, metformin, alanine transferase （ALT）, body mass index （BMI）, Urine albumin （Ualb）, and blood urea nitrogen （BUN） in total patients; and Cr, ALT, BMI and BUN in non-metformin treated patients; Cr and ALT in metformin-group. The lactate concentration increased with the increment of Cr levels, and reached its peak at Cr 111-130 μmol/L, and the optimal cutoff of Cr in predicting hyperlactacidemia was 96.5 μmol/L. Conclusions Metformin can increase the incidence of lactatemia in type 2 diabetic patients without renal dysfunction. Cr, ALT, and BMI are independent associated factors of blood lactic acid levels. There

关键词： diabetes mellitus lactic acid creatinine metformin cutoff

Spin Evolution of the Magnetar SGR J1935+2154

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Research in Astronomy and Astrophysics 2024年第1期24卷 201-211页

作者： Ming-Yu Ge Yuan-Pei Yang fang-jun lu Shi-Qi Zhou Long Ji Shuang-Nan Zhang Bing Zhang Liang Zhang Pei Wang Kejia Lee Weiwei Zhu Jian Li Xian Hou Qiao-Chu Li Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China South-Western Institute For Astronomy Research Yunnan UniversityKunming 650504China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Nevada Center for Astrophysics University of NevadaLas VegasNV 89154USA Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Department of Astronomy Peking UniversityBeijing 100871China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Yunnan Observatories Chinese Academy of SciencesKunming 650216China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 210023China

Fast radio bursts(FRBs)are short pulses observed in radio frequencies usually originating from cosmological *** discovery of FRB 200428 and its X-ray counterpart from the Galactic magnetar SGR J1935+2154suggests that at least some FRBs can be generated by ***,the majority of X-ray bursts from magnetars are not associated with radio *** fact that only in rare cases can an FRB be generated raises the question regarding the special triggering mechanism of *** we report long time spin evolution of SGR J1935+2154 until the end of *** to v and v,the spin evolution of SGR J1935+2154 could be divided into two *** first stage evolves relatively steady evolution until 2020 April *** the burst activity in2020,the spin of SGR J1935+2154 shows strong variations,especially for *** the burst activity in 2022October,a new spin-down glitch with△v/v=(-7.2±0.6)×10^(-6)is detected around MJD 59876,which is the second event in SGR J1935+*** the end,spin frequency and pulse profile do not show variations around the time of FRB 200428 and radio bursts 221014 and 221021,which supply strong clues to constrain the trigger mechanism of FRBs or radio bursts.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(SGR J1935+2154) X-rays:bursts

Long-term evolution of the X-ray flux of the Crab pulsar

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Radiation Detection Technology and Methods 2023年第1期7卷 48-55页

作者： Hai-Sheng Zhao Ming-Yu Ge Xiao-Bo Li Lin-Li Yan You-Li Tuo fang-jun lu Li-Ming Song Cong-Zhan Liu Shu Zhang Shuang-Nan Zhang Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadBeijing 100049China School of Mathematics and Physics Anhui JianZhu UniversityHefei 230601AnhuiChina

Purpose In order to carry out in-orbit calibration,the hard X-ray modulation telescope satellite(HXMT)has made a number of observations of Crab *** study the long-term evolution of the X-ray flux of the Crab pulsar with these observational *** We use nearly four years Crab pulsar’s data obtained by HXMT and the neutron star interior composition of explorer to test whether L_(x)∝L_(sd)^(α) holds for an individual pulsar,where L_(x) is the pulsed X-ray luminosity and Lsd is its spin-down *** also combine the earlier results obtained with PCA and HEXTE data(Yan et *** ApJ 865:21,2018)to get the long-term evolution characteristics of the Crab *** We find the X-ray flux evolution can be fitted by a linear correlation:L_(x)∝L_(sd)^(1.42±0.18).In soft X-ray energy band(1–10 keV)and hard X-ray energy band(27–250 keV),αdoes not change significantly with either energy or ***,this will need to be confirmed in *** example,the interpulse component of hard X-ray may follow L_(x)∝L_(sd)^(0.96±0.34),which may be different from the correlation of soft X-rays and main pulse *** the other hand,the hard X-ray flux evolution shows that the performance of high energy X-ray telescope(HE)onboard HXMT,such as effective area,is *** We conclude that the X-ray luminosity of the Crab pulsar closely correlates with its spin-down ***,the emission mechanism responsible for these phenomena remains not fully understood.

关键词： X-rays Crab pulsar Flux evolution Spin-down luminosity

Probing primordial gravitational waves: Ali CMB Polarization Telescope

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National Science Review 2019年第1期6卷 145-154页

作者： Hong Li Si-Yu Li Yang Liu Yong-Ping Li Yifu Cai Mingzhe Li Gong-Bo Zhao Cong-Zhan Liu Zheng-Wei Li He Xu Di Wu Yong-Jie Zhang Zu-Hui Fan Yong-Qiang Yao Chao-Lin Kuo fang-jun lu Xinmin Zhang Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences CAS Key Laboratory for Researches in Galaxies and Cosmology Department of AstronomyUniversity of Scienceand Technology of China Interdisciplinary Center for Theoretical Study University of Science and Technology of China National Astronomical Observatories Chinese Academy of Sciences Institute of Cosmology& Gravitation University of Portsmouth Key Laboratory of Particle Astrophysics Institute of High EnergyPhysics Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics ChineseAcademy of Sciences Department of Astronomy School of Physics Peking University Physics Department Stanford University

In this paper, we will give a general introduction to the Ali CMB Polarization Telescope(Ali CPT) project,which is a Sino–US joint project led by the Institute of High Energy Physics and involves many different institutes in China. It is the first ground-based Cosmic Microwave Background(CMB) polarization experiment in China and an integral part of China’s Gravitational-wave Program. The main scientific goal of the Ali CPT project is to probe the primordial gravitational waves(PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 5250 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope(Ali CPT-2) with more than 20 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years’ observation. Besides the PGWs, Ali CPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years’ observation will improve the current limit by two orders of magnitude.

关键词： primordial gravitational waves cosmic microwave background Ali CMB Polarization Telescope

Five-year in-orbit background of Insight-HXMT

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Radiation Detection Technology and Methods 2023年第1期7卷 34-47页

作者： Jin-Yuan Liao Shu Zhang Juan Zhang Gang Li Zhi Chang Yu-Peng Chen Ming-Yu Ge Jing Jin Xue-Feng lu Yuan You Xue-Lei Cao Yong Chen Yue Huang Wei-Chun Jiang Xiao-Bo Li Xu-fang Li Zheng-Wei Li Cong-Zhan Liu Ying Tan Yan-Ji Yang Yi-Fei Zhang Hai-Sheng Zhao fang-jun lu Yu-Peng Xu Jin-lu Qu Li-Ming Song Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityYuhu DistrictXiangtan 411105China University of Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of Sciences20A Datun RoadChaoyang DistrictBeijing 100012China

Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data *** The backgrounds of the three main payloads,i.e.,low-energy telescope,medium-energy telescope,and high-energy telescope,are *** evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of *** The major observational characteristics of the Insight-HXMT in-orbit background are presented,including the light curve,spectrum,geographical distribution,and long-term *** systematic error in background estimation is investigated for every *** The observational characteristics of the five-year in-orbit background are consistent with our knowledge of the satellite design and the space environment,and the background model is still valid for the latest observations of Insight-HXMT.

关键词： Instrumentation:detectors Space vehicles:instruments Methods:data analysis X-rays:general