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On the knee of Galactic cosmic rays in light of sub-TeV spectral hardenings

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chinese Physics C 2018年第7期42卷 113-122页

作者： Yi-Qing Guo1 2 Qiang Yuan1 3 1. Key Laboratory of Dark Matter and Space Astronomy purple mountain observatory chinese academy of sciences nanjing 2.0008 china 2. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences School of Astronomy and Space Science University of Science and Technology of China

More than fifty years after the discovery of the knee in the cosmic ray （CR） spectra, its physical origin remains a mystery. This is partly due to the ambiguity of the energy spectra of individual components. Recently, direct measurements from several space experiments found significant spectral hardenings of CR nuclei at ~200 GV. A joint modeling of the direct and indirect measurements may help to understand the experimental systematics and the physics of the knee. In this work, we update the phenomenological ＂poly-gonato＂ model to include the spectral hardenings, with a changing spectral index of γ ＋ β·logE. This modification gives a reasonable description of the CR spectra in a wide energy range. However, the fits to different data sets give different results. We find that the fit to the AMS-02 and CREAM data slightly favors a relatively low energy knee of the light components. In such a case, the expected all-particle spectra under-shoot the data, which may require an extra component of CRs. The fits to AMS-02 data and the light component （H＋He） data from the Tibet ASγ/ARGO-YBJ/WFCTA and KASCADE experiments give consistent results with the all-particle spectra. We further propose a possible physical realization of such a ＂modified poly-gonato＂ model of spectral hardenings by means of spatially-dependent diffusion of CRs. We find reasonably good agreement between the model predictions and the data for CR spectra, the secondary-to-primary ratios, and the amplitude of anisotropies.

关键词： cosmic ray knee spectrum propagation

Electron surfing acceleration in a current sheet of flares

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Science china(Physics,Mechanics & Astronomy) 2009年第11期52卷 1810-1812页

作者： WANG DeYu1 & LU QuanMing2 1 purple mountain observatory, nanjing 2.0008, china 2 School of Earth and Space sciences, University of Science and Technology of china, Hefei 230026, china purple mountain observatory Nanjing China School of Earth and Space sciences University of Science and Technology of China Hefei China

A model of electron acceleration in a current sheet of flares is studied by the analytical approximation solution and the test particle simulation. The electron can be trapped in a potential of propagating electrostatic wave. The trapped electron moving with the phase velocity v p of wave may be effectively accelerated by ev p/c × B z force along the outflow direction in the current sheet, if a criterion condition K > 0 for electron surfing acceleration is satisfied. The electron will be accelerated continuously until the electron de-trap from the wave potential at the turning point S.

关键词： electron acceleration electrostatic wave current sheet

On the Lower Energy Cutoff of Nonthermal Electrons in Solar Flares

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chinese Journal of Astronomy and Astrophysics 2001年第5期1卷 453-459页

作者： Wei－QunGan You－PingLi 等 purplemountainobservatory ChineseAcademyofSciencesNanjing210008 NationalAstronomicalObservatories Ch

A quantitative method to determine the lower energy cutoff (Ec) of power-law electron beams is established. We apply this method to the 54 hard X-ray events observed with BATSE/Compton Gamma Ray observatory (CGRO). The results show that about 75% of the observed broken double power-law spectra of hard X-rays can be explained by a lower energy cutoff in the power-law electron beams. The values of Ec, varying among the flares, are all greater than the usually accepted 20 keV! On average, E~ is about 69 keV. So high a lower energy cutoff of nonthermal electrons implies that nonthermal electrons might not be as important in powering solar flares as was previously thought. Further significance of this finding is discussed.

关键词： Sun: hard X-rays - Sun: gamma-rays - Sun: flares - Sun: particles TheSun

Optical results of the black hole microquasar SS 433

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 153-156页

作者： LI Hui1,2 & YAN JingZhi1,3 1 purple mountain observatory,chinese academy of sciences,nanjing 2.0008,china 2 Graduate University of chinese academy of sciences,Beijing 100049,china 3 Service d’Astrophysique,CEA Saclay and University Paris Diderot,91191 Gif-sur-Yvette,France purple mountain observatory Chinese Academy of Sciences Nanjing China Graduate University of chinese academy of sciences Beijing China Service d’Astrophysique CEA Saclay and University Paris Diderot Gif-sur-Yvette France

We present optical spectroscopic observations of SS 433 during different precessional and orbital *** 2004,2007 and 2008 data provide us a good chance to study the variability of the Hα line at different orbital phases for nearly the same disk *** data show that the Hα of SS 433 usually had a symmetric profile between orbital phases 0.25-0.75,while an asymmetric structure with a strong red peak was observed for other orbital *** suggest that the orbital variability of Hα emission is connected with accretion flow from the donor star to the accretion *** addition,we attribute the dramatic increase of Hα emission during our 2007 observational run,which had a time scale of one day,to the emergence of strong jets.

关键词： high-mass X-ray binary black hole spectroscopy outflow wind relativistic jet

THEORETICA　LCALCULATION　OF　ATOMIC　AND　MOLECULAR　DATA

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原子与分子物理学报 1997年第2期 35-37页

作者： Pei Chunchuan purple mountain observatory Academia Sinica nanjing 2.0008

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ＴＨＥＯＲＥＴＩＣＡＬＣＡＬＣＵＬＡＴＩＯＮＯＦＡＴＯＭＩＣＡＮＤＭＯＬＥＣＵＬＡＲＤＡＴＡＰｅｉＣｈｕｎｃｈｕａｎＰｕｒｐｌｅＭｏｕｎｔａｉｎＯｂｓｅｒｖａｔｏｒｙＡｃａｄｅｍｉａＳｉｎｉｃａＮａｎｊｉｎｇ２１０００８ＡＢＳＴＲＡＣＴＢｙｕｓｉｎ...

关键词： Atomic and molecular data Interstellar molecules Equation of state Molecular lines observation

Unusually Broadened Spectral Profiles Observed in Solar Prominences

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chinese Journal of Astronomy and Astrophysics 2004年第4期4卷 377-389页

作者： HuiLi Jian-QiYou EijiroHiei purplemountainobservatory ChineseAcademyofSciencesNanjing210008 NationalAstronomicalobservatoryofJapan MitakaTokyo181-8588Japan

After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at purple mountain observatory and the 25 cm coronagraph at the Norikura Solar observatory, we found that about 28% of them show small spatial scale (6''–8'') and short time scale (tens of seconds to a few minutes), unusual large broadening and large shift velocities in spectral lines including Hα, Hβ, H, Ca II H, Ca II K, Ca II 8542?, He I D3 and He I 10830?. We present in detail two typical events observed respectively on 2002 May 27 and 1981 August 2. The full-width at half maximum of the widest profile of the 2001 prominence is 1.8? for Hα and 2.9 ? for He I 10830?, while that of the 1981 prominence is 5.3 ? for Hβ, 3.6 ? for Ca II K, 4.0 ? for Ca II H and 2.8 ? for He I D3. Such broadenings generally occur at a level of several-thousand kilometres above the chromosphere. Further, most of these prominences manifest a rotation of (0.4–1.35)×10-2 rads s?1 pointing to the Sun and large line-of-sight velocities of 20–200 km s?1. Some of these events correspond in time to an enhancement or a small peak in the GOES X-ray flux, indicating the existence of high energy process at work. These prominences generally display discernible changes in the Hα morphology around the time of large broadening, but do not show Hα brightening or overall eruption except for a few small surge-like events, hence, they are hardly observed in daily Hα patrols. According to the characteristics of their Hα structures and spectral properties, we infer these events are small-scale eruptions similar to nano-flares, which may contribute to the mass and energy transported into the corona. Large turbulent velocities of 25–120 km s?1 are responsible for the observed broadenings.

关键词： sun: prominences line: profiles turbulence

Diffuse interstellar absorption bands

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Science china(Physics,Mechanics & Astronomy) 2009年第4期52卷 489-501页

作者： XIANG FuYuan1,2,LIANG ShunLin2 & LI AiGen2,3 1 Faculty of Materials,Photoelectronics and Physics,Xiangtan University,Xiangtan 411105,china 2 Department of Physics and Astronomy,University of Missouri,Columbia,MO 65211,USA 3 purple mountain observatory,chinese academy of sciences,nanjing 2.0008,china Faculty of Materials Photoelectronics and Physics Xiangtan University Xiangtan China Department of Physics and Astronomy University of Missouri Columbia USA purple mountain observatory Chinese Academy of Sciences Nanjing China

The diffuse interstellar bands(DIBs) are a large number of absorption bands that are superposed on the interstellar extinction curve and are of interstellar origin. Since the discovery of the first two DIBs in the 1920s,the exact nature of DIBs still remains unclear. This article reviews the history of the detections of DIBs in the Milky Way and external galaxies,the major observational characteristics of DIBs,the correlations or anti-correlations among DIBs or between DIBs and other interstellar features(e.g. the prominent 2175 Angstrom extinction bump and the far-ultraviolet extinction rise),and the proposed candidate carriers. Whether they are also present in circumstellar environments is also discussed.

关键词： astrophysics interstellar matter interstellar extinction diffuse interstellar band circumstellar environment

Solar Partial N-burst

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chinese Journal of Astronomy and Astrophysics 2003年第4期3卷 381-390页

作者： Zong-JunNing Yu-YingLiu Qi-JunFu Fu-YingXu NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012 purplemountainobservatory ChineseAcademyofSciencesNanjing210008

We present a new sub-class of type Ⅲ solar radio burst at the highfrequencies around 6.0 GHz. In addition to a descending and an ascending branch on the dynamicspectrum, it has an inverted morphology different from the simple type U-burst. We call it 'partialN-burst' because it is interpreted as the known N-burst minus its first branch. The partial N-burstpresented here was detected among a reverse slope type Ⅲ (RS-Ⅲ) burst group prior to the type Ⅴsolar radio continuum and was simultaneously recorded by two spectrometers at the NationalAstronomical Observatories, chinese academy of sciences (NAOC, 5.20-7.60 GHz) and at purple mountainobservatory (PMO, 4.50-7.50 GHz) on 1999 August 25. After the N-burst and M-burst, the partialN-burst is a third piece of evidence for a magnetic mirror effect in solar radio observation, whenthe same electron is reflected at a pinched foot of a flare loop.

关键词： sun: radio radiation sun: magnetic fields

THE MORPHOLOGICAL PROPERTIES OF TWO LIMB FLARES OCCURRING IN AR 5629

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天文研究与技术 1990年第4期 179-340页

作者： Fan Zhongyupurple mountain observatory, chinese academy of sciences, nanjing, 2.0008, china

AR 5629 is a complicated active region with δ magnetic classification,By use of aslit-jaw system and a Reticon system attached to the multiple wavelength solarspectro-graph at purple mountain observatory,we obtained ... 详细信息

关键词： purple attached burst Figure surge grateful Solar impulsive analysed