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Not enough evidence to support the correlation between gamma-ray bursts and foreground galaxy clusters in the Swift Era

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Research in Astronomy and Astrophysics 2010年第6期10卷 533-540页

作者： Jing Wang jian-yan wei National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The correlation between distant Gamma-Ray Bursts （GRBs） and foreground galaxy clusters is re-examined by using the well localized （with an accuracy down to a few arcsec） Swift/XRT GRBs. The galaxy clusters are compiled from both the X-ray selected ROSAT brightest cluster sample （BCS） and the BCS extension by requiring δ ≥ 0° and b ≥ 20°. The Swift/XRT GRBs fulfilling the above selection criteria are cross-correlated with the clusters. Both Nearest-Neighbor analysis and the angular two-point cross-correlation function show that there is not enough evidence supporting the correlation between the GRBs and foreground clusters. We suggest that the non-correlation is probably related to the GRB number-flux relation slope.

关键词： gamma rays bursts -- galaxies clusters general -- methods statistical

A pilot study of catching high-z GRBs and exploring circumburst environment in the forthcoming SVOM era

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Research in Astronomy and Astrophysics 2020年第8期20卷 211-216页

作者： Jing Wang Yu-Lei Qiu jian-yan wei Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

Rapid spectroscopy of GRB afterglows is an important and hard *** on the archival XSGRB spectral database,we here perform a pilot study on the afterglow's spectroscopy in the forthcoming SVOM era in two ***,our simulation indicates that the color acquired from the SVOM/VT blue and red channels is effective in discriminating between low-z(z≤3)and distant GRB candidates until z^***,by doubling the sample size,we find that the previously proposed global photoionization response of the circumburst gas to the prompt emission(i.e.,the CIV/CII-L(iso)/E2peak relationship)is roughly *** the confirmation is dissatisfactory at the large L(iso)/E2peak *** believe that this issue can be further addressed in the SVOM era by a larger spectroscopy sample,thanks to its capability of rapid identification of optical candidates of afterglow and its anti-solar pointing strategy.

关键词： gamma ray bursts:general techniques:photometric techniques:spectroscopic methods:statistical

Possible evidence of destroying small PAH particles by radiation from AGNs

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Research in Astronomy and Astrophysics 2015年第2期15卷 199-206页

作者： Qi-Chen Feng Jing Wang jian-yan wei National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

The issue of destroying small polycyclic aromatic hydrocarbon （PAH） par- ticles by radiation from AGNs is examined through optical narrow-emission line ra- tios of a sample of type II AGNs. We find that narrow-line ratios [OI]λ6300/Ha and [SII]λ6716, λ6731/Hα have prominent correlations with the PAH 11.3/7.7 ratio in our selected sample of AGNs. Because of the marginal （and in some cases no） dependence of the PAH ratio on the gas metallicity, a possible explanation for the correlations is the destruction of small PAH particles by the hard ionizing field associated with the AGNs.

关键词： infrared: ISM quasars: emission lines galaxies: active galaxies: AGN methods: statistical

Extending the Eigenvector 1 space to the optical variability of quasars

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Chinese Journal of Astronomy and Astrophysics 2009年第5期9卷 529-537页

作者： Yu-Feng Mao Jing Wang jian-yan wei National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

We introduce a new physical parameter, the optical variability amplitude, to the well-established Eigenvector 1 space of quasars and test a sample of long-term B- band light curves of 42 Palomar-Green quasars monitored by Giveon et al. We find that the optical variability amplitude strongly correlates with the intensity ratio of FeⅡ to Hβ, Hβ width and peak luminosity at 5007A. We briefly discuss the physical meaning of our findings and suggest that the Eddington ratio may be a key factor in determining a quasar＇s variability.

关键词： galaxies active -- quasars general

Photometric Monitoring of ROSAT-Selected Weak Line T Tauri Stars

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Chinese Journal of Astronomy and Astrophysics 2006年第6期6卷 716-722页

作者： Li-Feng Xing Xiao-Bin Zhang jian-yan wei National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Technology and Physics Zhengzhou University of Light Industry Zhengzhou 450002

We monitored the light curves of 22 weak-line T Tauri stars （WTTSs） discovered among the X-ray sources in the field of the Taurus-Auriga cloud. For 12 of the 22 WTTSs photometric periodic variability is confirmed and their rational periods are determined using Phase Dispersion Minimization （PDM） and Fourier analysis. Most of them are found to have periods shorter than one day. This gives further evidence for the spin up of solar-type stars predicted by the models of angular momentum evolution of pre-main sequence stars.

关键词： stars late-type- stars pre-main sequence- stars rotation

Preventing Fatal Risk through Outpatient Medical Insurance:Evidence from Urban Employee Basic Medical Insurance System in Xinjiang Uighur Autonomous Region,China

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Biomedical and Environmental Sciences 2014年第7期27卷 544-551页

作者： JING Ming Xia LI Xiao Ju jian wei yan Medical School of Shihezi University Department of Health Policy and Management School of Public HealthPeking University Health Science Centre

Disease burden from non-communicable diseases （NCDs） has attracted worldwide attention. The 2010 World Health Organization Global Status Report on Non -communicable Diseases showed that deaths caused by NCDs exceede... 详细信息

关键词： Preventing Fatal Risk through Outpatient Medical Insurance mode

Variability of Soft X-ray Spectral Shape in Blazars Observed by ROSAT

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Chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 117-126页

作者： Lin-Peng Cheng Yong-Heng Zhao jian-yan wei National Astronomical Observatories Chinese Academy of SciencesBeijing 100012

In previous paper we have shown that the soft X-ray spectra of two types of Seyfert 1 galaxies behave statistically differently with increasing intensity. In order to see how the spectrum of blazars changes, we made plots of Hardness Ratio 1 versus Count Rates (HR1-Cts) for 18 blazars observed by ROSAT/PSPC. According to our criteria, ten showed a positive HR1-Cts correlation, two a negative correlation, and the remaining six, no clear correlation. Thus, most blazars of our sample show a hardening spectrum during overall flux increase, though some vary randomly. By investigating the photon index of these objects and different radiation theories, we argue that relative dominance between the synchrotron and inverse Compton emission in the soft X-ray band can well account for the differing spectral behaviours and that the different spectral variations might represent a sequence of synchrotron peaked frequency.

关键词： galaxies active-galaxies X-ray-blazar spectrum

MiCPhot:A prime-focus multicolor CCD photometer on the 85-cm Telescope

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Chinese Journal of Astronomy and Astrophysics 2009年第3期9卷 349-366页

作者： Ai-Ying Zhou Xiao-Jun jiang yan-Ping Zhang jian-yan wei National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Department of Astronomy Beijing Normal University Beijing 100875 China

We describe a new BVRI multicolor CCD photometric system situated at the prime focus of the 85-cm telescope at the Xinglong Station of NAOC. Atmospheric extinction effects, photometric accuracy and color calibration dependence of the system are investigated. Additional attention was paid to giving observers guidance in estimating throughput, detection limit, signal-to-noise ratio and exposure time.

关键词： instrumentation photometers CCD photometer- techniques photometric

Rotation Periods of Nine ROSAT Selected Solar-Type Stars

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Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 551-557页

作者： Li-Feng Xing Shuang-Yi Zhao wei Su yan Shen Xiao-Bin Zhang jian-yan wei Department of Technology and Physics Zhengzhou Unversity of Light Industry Zhengzhou 450002 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Physics Xingtai University Xingtai 054001

We monitored 16 X-ray selected young solar-type stars for light variation and found appreciable periodic light variability with amplitudes of a few hundredths of a magni- tude in nine of the objects. Using the method of Phase Dispersion Minimization （PDM） and Fourier analysis （software PERIOD04）, the rotation periods of these stars were determined from the photometric data. The rotation periods of all nine stars are shorter than about 3 days. It is suggested that, as with the Pleiades cluster, small amplitude light variations are quite common among young solar-type stars with rotation periods around 3 days or less. This gives further evidence for the spin up of solar-type stars predicted by models of angular momentum evolution of pre-main sequence stars.

关键词： stars: late-type - stars: pre-main sequence - stars: rotation