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The abundance of massive compact galaxies at 1.0

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Research in Astronomy and Astrophysics 2019年第10期19卷 109-120页

作者： Shi-Ying Lu Yi-Zhou Gu Guan-Wen Fang qi-rong yuan Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 China Institute for Astronomy and History of Science and Technology Dali UniversityDali 671003 China

Based on a large sample of massive(M* 1010 M⊙) compact galaxies at 1.0 < z < 3.0 in five 3 D-HST/CANDELS fields, we quantify the fractional abundance and comoving number density of massive compact galaxies as a function of redshift. The samples of compact quiescent galaxies(cQGs) and compact star-forming galaxies(cSFGs) are constructed by various selection criteria of compact galaxies in the literature, and the effect of compactness definition on abundance estimate has proven to be remarkable,particularly for the cQGs and cSFGs at high redshifts. Regardless of the compactness criteria adopted,their overall redshift evolutions of fractional abundance and number density are found to be rather *** samples of the cQGs exhibit a sustained increase in number density from z ~ 3 to 2 and a plateau at 1 < z < 2. For massive cSFGs, a plateau in the number density at 2 < z < 3 can be found, as well as a continuous drop from z ~ 2 to 1. The evolutionary trends of the cQG and cSFG abundances support the scenario that the cSFGs at z≥ 2 may have been rapidly quenched into quiescent phase via violent dissipational processes, such as major merger and disk instabilities. The rarity of the cSFGs at lower redshifts(z < 1) can be interpreted by the decrease of gas reservoirs in dark matter halos and the consequent low efficiency of gas-rich dissipation.

关键词： galaxies high-redshift-galaxies massive-compact-galaxies evolution-galaxies

Statistical Cluster-QSO Weak Lensing in the Sloan Digital Sky Survey

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Chinese Journal of Astronomy and Astrophysics 2006年第5期6卷 521-529页

作者： Zhong-Lue Wen Yan-Bin Yang Xu Zhou qi-rong yuan Jun Ma National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Physics Nanjing Normal University Nanjing 210097

We investigate the cross-correlation between galaxy clusters and QSOs using Sloan Digital Sky Survey （SDSS） DR4 - 5000 deg^2 data. With photometric redshifts of galaxies, we select galaxy clusters based on the local projected densities of LRGs brighter than Mr′ = -22. The QSOs are from the main sample of SDSS QSO spectroscopic survey to i′ = 19. A significant positive correlation is found between the clusters and QSOs. Under the assumption that the signal is caused by gravitational lensing, we fit the signal with singular isothermal sphere （SIS） model and NFW profile halo model. The velocity dispersion σv = 766 km s^-1 is derived for the best-fit of SIS model. Best-fit for the NFW model requires the dark matter halo mass within 1.5 h^-1 Mpc to be 4.6 × 10^14 h^-1 M⊙. The mass parameter Ωcl of the cluster sample is deduced as 0.077 with the SIS model and 0.083 with the NFW model. Our results of Ωcl are smaller than those given by Croom ＆ Shanks and by Myers et al.

关键词： cosmology observations - galaxies clusters general - quasars general - gravitational lensing

A Fourteen-Band Photometric Study of A2443

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Chinese Journal of Astronomy and Astrophysics 2007年第1期7卷 71-80页

作者： Zhong-Lue Wen Yan-Bin Yang qi-rong yuan Xu Zhou Jun Ma Zhao-Ji Jiang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Physics Nanjing Normal University Nanjing 210097

We present a multi-color photometric study of the galaxy cluster A2443 （z = 0.108） with the Beijing-Arizona-Taiwan-Connecticut （BATC） system. The spectral energy distributions （SEDs） in 14 intermediate bands are obtained for 5975 detected from -ldeg^2 of the BATC images. Color-color diagrams are used for star-galaxy separation, then a photometric redshift technique is applied to the galaxy sample for cluster membership determination. There are 301 galaxies with photometric redshifts between 0.08 and 0.14 determined as member candidates of A2443, including 289 new ones. Based on this enlarged sample, the luminosity function and color magnitude relation of the cluster are studied. With an evolutionary synthesis model, we find that the fainter galaxies tend to have longer time scales of star formation than the brighter ones. Morphologically, we show an elongated spatial distribution associating with the galaxy cluster ZwCl 2224.2＋1651, which contains more blue galaxies. This result indicates that galaxy cluster ZwCl 2224.2＋1651 may be falling into A2443, and cluster-cluster interaction could have triggered star formation activities in ZwCl 2224.2＋1651.

关键词： galaxies clusters individual A2443-galaxies distances and redshifts

The Orthogonal Bases of Exponential Functions Based on Moran-Sierpinski Measures

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1804-1824页

作者： qi rong DENG Xing Gang HE Ming Tian LI yuan Ling YE School of Mathematics and Statistics Center for Applied Mathematics of Fujian Province&Key Laboratory of Analytical Mathematics and Applications(Ministry of Education)Fujian Normal UniversityFuzhou350117P.R.China School of Mathematics and Statistics Key Lab NAA-MOE and Hubei Key Lab-Math.Sci.Central China Normal UniversityWuhan430079P.R.China School of Mathematical Sciences&South China Research Center for Applied Mathematics and Interdisciplinary Studies South China Normal UniversityGuangzhou510631P.R.China

Let An∈M2(ℤ)be integral matrices such that the infinite convolution of Dirac measures with equal weightsμ{A_(n),n≥1}δA_(1)^(-1)D*δA_(1)^(-1)A_(2)^(-2)D*…is a probability measure with compact support,where D={(0,0)^(t),(1,0)^(t),(0,1)^(t)}is the Sierpinski *** prove that there exists a setΛ⊂ℝ2 such that the family{e2πi〈λ,x〉:λ∈Λ} is an orthonormal basis of L^(2)(μ{A_(n),n≥1})if and only if 1/3(1,-1)A_(n)∈Z^(2)for n≥2 under some metric conditions on A_(n).

关键词： Moran-Sierpinski measures orthonormal basis of exponential functions self-affine measures spectral measures

About 300 days Optical Quasi-periodic Oscillations in the Long-term Light Curves of the Blazar PKS 2155-304

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Research in Astronomy and Astrophysics 2022年第8期22卷 284-293页

作者： qi Zheng Xue-Guang Zhang qi-rong yuan School of Physics and Technology Nanjing Normal UniversityNanjing 210023China

Based on the long-term light curves collected from the Catalina Sky Survey(CSS)(from 2005 to 2013)and the All-Sky Automated Survey for Supernovae(ASAS-SN)(from 2014 to 2018),optical quasi-periodic oscillations(QPOs)about 300 days can be well determined in the well-known blazar PKS 2155-304 through four different methods:the generalized Lomb-Scargle periodogram(GLSP)method,the weighted wavelet Z-transform technique,the epoch-folded method and the redfit *** GLSP determined significance level for the periodicity is higher than 99.9999%based on a false alarm *** redfit provided confidence level for the periodicity is higher than 99%in the ASAS-SN light curve,after considering the effects of red *** on continuous autoregressive process created artificial light curves,the probability of detecting fake QPOs is lower than 0.8%.The determined optical periodicity of 300 days from the CSS and ASAS-SN light curves is well consistent with the reported optical periodicity in the ***,three possible models are discussed to explain the optical QPOs in PKS 2155-304:the relativistic frame-dragging effect,the binary black hole model and the jet precession model.

关键词： (galaxies:)BL Lacertae objects:individual(PKS 2155-304) galaxies:active (galaxies:)quasars:supermassive black holes

Multicolor photometry of the galaxy cluster A98: substructures and star formation properties

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Research in Astronomy and Astrophysics 2010年第1期10卷 1-21页

作者： Li Zhang qi-rong yuan Xu Zhou Zhao-Ji Jiang Yan-Bin Yang Jun Ma Jiang-Hua Wu Zhen-Yu Wu Department of Physics Nanjing Normal University Nanjing 210046 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

An optical photometric observation with the Beijing-Arizona-Taiwan- Connecticut （BATC） multicolor system is carried out for A98 （z =0.104）, a galaxy cluster with two large enhancements in X-ray surface brightness. Spectral energy distributions （SEDs） covering 15 intermediate bands are obtained for all sources detected down to V - 20 mag in a field of 58′× 58′. After star-galaxy separation with colorcolor diagrams, a photometric redshift technique is applied to the galaxy sample for further membership determination. The color-magnitude relation is taken as a further restriction of the early-type cluster galaxies. As a result, a list of 198 faint member galaxies is achieved. Based on the newly generated sample of member galaxies, the dynamical substructures, A98N, A98S, and A98W, are investigated in detail. A separate galaxy group, A98X, is also found to the south of the main concentration of A98, which is gravitationally unbound to A98. For 74 spectroscopically confirmed member galaxies, the environmental effect on the star formation history is investigated. The bright galaxies in the core region are found to have shorter time scales of star formation, longer mean stellar ages, and higher interstellar medium metallicities, which can be interpreted in the context of the hierarchical cosmological scenario.

关键词： galaxies clusters individual (A98) - galaxies distances and redshifts - galaxies kinematics and dynamics - galaxies evolution - methods data analysis

Advance on Chinese Medicine for Hypertensive Renal Damage:Focus on the Complex Molecular Mechanisms

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Chinese Journal of Integrative Medicine 2024年第10期30卷 938-948页

作者： LU Yan XIE Xue-na XIN qi-qi yuan rong MIAO Yu CONG Wei-hong CHEN Ke-ji Laboratory of Cardiovascular Diseases Xiyuan Hospital of China Academy of Chinese Medical SciencesBeijing100091China School of Pharmacy Macao University of Science and TechnologyTaipaMacao999078China National Clinical Research Center for Chinese Medicine Cardiology Beijing100091China

Hypertensive renal damage(HRD)is a major cause of end-stage renal *** the causes of end-stage renal disease,HRD accounts for nearly 34%of the total number of *** treatment is primarily drug-based,but therapeutic efficacy is less effective and can have serious side *** medicine(CM)has significant advantages in the treatment of *** is rich in various active ingredients and has the property of targeting multiple targets and ***,the regulatory network of CM on disease is complex.A large number of CM have been employed to treat HRD,either as single applications or as part of compound *** key possible mechanisms of CM for HRD include regulation of the renin-angiotensin-aldosterone system,antioxidation,anti-inflammation,rescue of endothelial function,regulation of vasoactive substance secretion and obesity-related factors,*** review summarized and discussed the recent advance in the basic research mechanisms of CM interventions for HRD and pointed out the challenges and future prospects.

关键词： Chinese medicine hypertensive renal damage molecular mechanisms research progress

Multicolor photometry of the nearby galaxy cluster A119

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Research in Astronomy and Astrophysics 2012年第10期12卷 1381-1401页

作者： Jin-Tao Tian qi-rong yuan Xu Zhou Zhao-Ji Jiang Jun Ma Jiang-Hua Wu Zhen-Yu Wu Tian-Meng Zhang Hu Zou National Astronomical Observatories Chinese Academy of Sciences Beiiing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academyof Sciences Beijing 100012 China Department of Physics Nanjing Normal University Nanjing 210046 China Department of Astronomy Beijing Normal University Beijing 100875 China

This paper presents multicolor optical photometry of the nearby galaxy cluster Abell 119 （z = 0.0442） with the Beijing-Arizona-Taiwan-Connecticut system of 15 intermediate bands. Within the BATC field of view of 58＇× 58＇, there are 368 galaxies with known spectroscopic redshifts, including 238 member galaxies （called sample I）. Based on the spectral energy distributions of 1376 galaxies brighter than iBATC ---- 19.5, the photometric redshift technique and the color-magnitude relation of early-type galaxies are applied to select faint member galaxies. As a result, 117 faint galaxies were selected as new member galaxies. Combined with sample I, an enlarged sample （called sample II） of 355 member galaxies is obtained. Spatial distribution and localized velocity structure for two samples demonstrate that A119 is a dynami- cally complex cluster with at least three prominent substructures in the central region within 1 Mpc. A large velocity dispersion for the central clump indicates a merging along the line of sight. No significant evidence for morphology or luminosity segrega- tions is found in either sample. With the PEGASE evolutionary synthesis model, the environmental effect on the properties of star formation is confirmed. Faint galaxies in the low-density region tend to have longer time scales of star formation, smaller mean stellar ages, and lower metallicities in their interstellar medium, which is in agreement with the context of the hierarchical cosmological scenario.

关键词： galaxies: clusters: individual (A119)- galaxies: distances and redshifts-- galaxies: evolution-- galaxies: kinematics and dynamics-- methods: data analysis

Metal abundance and kinematical properties of the M81 globular cluster system

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Research in Astronomy and Astrophysics 2013年第4期13卷 399-410页

作者： Jun Ma Zhen-Yu Wu Tian-Meng Zhang Song Wang Zhou Fan Jiang-Hua Wu Hu Zou Cui-Hua Du Xu Zhou qi-rong yuan National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences Graduate University of Chinese Academy of Sciences Department of Astronomy Beijing Normal University College of Physical Sciences Graduate University of Chinese Academy of Sciences Department of Physics Nanjing Normal University

We present metal abundance properties of 144 globular clusters associated with M81. These globulars represent the largest globular cluster sample in M81 till now. Our main results are： the distribution of metallicities is bimodal, with metallicity peaks at [Fe/H] -1.51 and -0.58, and the metal-poor globular clusters tend to be less spatially concentrated than the metal-rich ones; the metal-rich globular clusters in M81 do not demonstrate a centrally concentrated spatial distribution like the metalrich ones in M31 do; like our Galaxy and M31, the globular clusters in M81 have a small radial metallicity gradient. These results are consistent with those obtained from a small sample of M81 globular clusters. In addition, this paper shows that there is evidence that a strong rotation of the M81 globular cluster system around the minor axis exists, and that rotation is present in the metal-rich globular cluster subsample, but the metal-poor globular cluster subsample shows no evidence of rotation. The most significant difference between the rotation of the metal-rich and metal-poor globular clusters occurs at intermediate projected galactocentric radii. Our results confirm the conclusion of Schroder et al. that M81＇s metal-rich globular clusters at intermediate projected radii are associated with a thick disk of M81.

关键词： galaxies: individual (M81) -galaxies: star clusters globular clusters:general