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New evidence for lack of CMB power on large scales

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Science china(Physics,Mechanics & astronomy) 2010年第3期53卷 567-570页

作者： liu hao1 & li tipei1,2.3 1 {2. laboratory of particle astrophysics, institute of high energy Physics, chinese academy of sciences, beijing 100049, china 2.Department of Physics & Center for astrophysics, Tsinghua University, beijing 100084, china 3 Department of Engineering Physics & Center for astrophysics, Tsinghua University, beijing 100084, china 1. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Department of Physics & Center for Astrophysics Tsinghua University Beijing 100084 China3. Department of Engineering Physics & Center for Astrophysics Tsinghua University Beijing 100084 China

A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.

关键词： cosmology cosmic microwave background data analysis

Inconsistency between WMAP data and released map

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chinese Science Bulletin 2010年第10期55卷 907-909页

作者： liu hao1 & li tipei1,2.3 1 {2. laboratory of particle astrophysics,institute of high energy Physics,chinese academy of sciences,{12. 100049,china 2.Department of Physics & Center for astrophysics,Tsinghua University,{12. 100084,china 3 Department of Engineering Physics & Center for astrophysics,Tsinghua University,{12. 100084,china key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Department of Physics & Center for astrophysics Tsinghua University Beijing China Department of Engineering Physics & Center for astrophysics Tsinghua University Beijing China

A remarkable inconsistency between the calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission,which is the input for map-making,and the cosmic microwave background (CMB) temperature maps published by the WMAP team is revealed,indicating that there must exist a serious problem in the map making routine of the WMAP *** inconsistency is easy to be confirmed without the use of WMAP map-making *** view of the importance of this issue for cosmology study,we invite readers to check it by themselves.

关键词：威尔金森微波各向异性探测器 WMAP 地图制作宇宙微波背景有序数据制作软件 TOD CMB

Bifurcation timescales in power spectra of black hole binaries and ultraluminous X-ray sources

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 177-182页

作者： WANG TaiShan1 & li tipei1,2.1 Department of Physics & Center for {2.physics,Tsinghua University,beijing 100084,china 2.key laboratory of particle {2.physics,institute of high energy Physics,{12. academy of sciences,beijing 100049,china Tsinghua Univ Dept Phys Beijing 100084 Peoples R China Tsinghua Univ Ctr Astrophys Beijing 100084 Peoples R China chinese Acad Sci Inst High Energy Phys Key Lab Particle Astrophys Beijing 100049 Peoples R China

For black hole binaries(BHBs) and active galactic nuclei(AGNs),bifurcation timescales(BTs) Δtb exist,below which time-domain power is significantly higher than the corresponding Fourier ***-periodic oscillations(QPOs) are removed from the Fourier spectra of BHBs.A relationship between BT,black hole mass and bolometric luminosity is *** anti-correlation between BT and luminosity of Cyg X-1 is *** removing the QPOs,BTs are also obtained for two ultraluminous X-ray sources(ULXs),M82.X-1 and NGC5408 *** results support that they harbor intermediate mass black holes(IMBHs).

关键词： black hole binary ultraluminous X-ray source power spectral density data analysis

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(2..5) bulk metallic glass up to 2. GPa

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Science china(Physics,Mechanics & astronomy) 2005年第3期48卷 319-324页

作者： li Gong 1, 2., ZHAN Zaiji 2., liu Jing 3 , YUN Jinku 1 , SUN liling 2., liu Riping 1 , ZHANG Jun 2.& WANG Wenkui 1, 2.1. key laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, china 2. Center for Condensed Matter Physics, institute of Physics, chinese academy of sciences, beijing 100080, china 3. BSRF, institute of high energy Physics, chinese academy of sciences, beijing 100039, china 1. key laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be2..5 bulk metallic glass (BMG) is investigated at room temperature up to 2. GPa using in-situ high pressure {2. dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Hard X-ray lags of Cygnus X-1 on short timescales

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 150-152页

作者： JIN Jing1,LU Yu2.3,QU JinLu2.& li {2.,2.1 Department of Engineering Physics & Center for astrophysics,Tsinghua University,beijing 100084,china 2.key laboratory of particle astrophysics,institute of high {12. Physics,chinese academy of sciences,beijing 100049,china 3 Graduate University of chinese academy of sciences,beijing 100049,china 1. Department of Engineering Physics & Center for astrophysics Tsinghua University Beijing 100084 China2. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Calculating the time lags over different timescales using the cross-correlation technique may lead to a biased estimate of small *** a timescale for lightcurve binning,we propose to subtract the local average instead of the global average during the cross-correlation,in order to filter variations on timescales larger than the bin *** new method allows us to make an unbiased estimate of the time lags using RXTE/PCA data on timescales as small as-5 ms,where the Fourier technique becomes *** calculate the time lag spectra of Cygnus X-1 at different spectral states with the new method,and find that the source appears to have similar X-ray lags on small timescales independent of its spectral states.

关键词： spectral lags Cygnus X-1 data analysis

The time lag spectrum of Cir X-1 on its normal branch

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 60-63页

作者： QU JinLu1,LU Yu1,2.DING GuoQiang3,ZHANG Fan1,LEI YaJuan1 & li ZhiBing1 1 key {2. for particle astrophysics,institute of high energy Physics,chinese academy of sciences,beijing {12.,china 2.Graduate University of chinese academy of sciences,beijing {12.,china 3 Urumqi Observatory,NAOC Urumqi 830011,china 1. key laboratory for {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Urumqi Observatory NAOC Urumqi 830011 China

In the radiation-hydrodynamics model,the time lag and fractional root-mean-squared(rms) amplitude as a function of emitted photon energy should show a minimum on the normal branch *** has been seen in the Z-sources Cyg X-2.and GX ***,using the observations from the Rossi X-ray Timing Explorer(RXTE),we study the energy dependence of normal branch QPOs in the peculiar Z-source Cir *** discuss the results in the context of radiation-hydrodynamics and the Comptonization model.

关键词： Cir X-1 temporal variability QPO time lag

Simulation of the in-flight calibration of the collimator alignment and PSF for HXMT

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 47-50页

作者： XIONG Shaolin,li XinQiao,QU JinLu & LU FangJun key laboratory for particle astrophysics,institute of high energy Physics,chinese academy of {12.(CAS),beijing 100049,china 1. key laboratory for {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences (CAS) Beijing 100049 China

The Hard X-ray Modulation Telescope(HXMT) is an X-ray astronomical satellite in 1-2.0 keV,consisting of three collimated *** present the in-flight calibration approach of the collimator alignment and Point Spread Function(PSF) for HXMT,using both the direct fitting method and the imaging *** to observational simulations of the Crab Nebula,we find that these two methods produce almost the same calibration accuracy of the alignment,and with a one-day scanning observation,the alignment can be calibrated to better than 0.45' and 0.1' along the wide and narrow directions of the Field of View(FOV) for a detector module,which corresponds to a localization accuracy of better than 0.1' and meets the scientific requirement.

关键词： HXMT alignment PSF calibration

light collection of the POLAR detector

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,li YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan key {2. of particle astrophysics,institute of high energy Physics,chinese academy of sciences,beijing {12.,china 1. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-350 *** light collection of 2.0 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4×4 bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

SVOM gamma ray monitor

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,li YanGuo,ZHANG YongJie & ZHANG ShuangNan key {2. of particle astrophysics,institute of high energy Physics,chinese academy of sciences,beijing {12.,china 1. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other {2.-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich