Stellar kinematics and populations out to 1.5 effective radii in the elliptical galaxy NGC 4636     

Shi-Bi Pu    Zhan-Wen Han  National Astronomical Observatory /Yunnan Observatory  Chinese Academy of Sciences  Kunming  China Graduate University of Chinese Academy of Sciences  Beijing  China Key Laboratory of the Structure  Evolution of Celestial Objects  China 《中国天文和天体物理学报》2011,(8)

We present high quality long slit spectra along the major and minor axes out to 1.5 effective radii of the massive galaxy NGC 4636 taken by the Hobby-Eberly Telescope. Using the Fourier Correlation Quotient method,we measured the stellar line-of-sight velocity distribution along the axes. Furthermore,six Lick/IDS indices(Hβ,Mgb,Fe5015,Fe5270,Fe5335,Fe5406) are derived from the clean spectrum. By comparing the measured absorption line strengths with the predictions of Simple Stellar Population(SSP) models,we...  相似文献   

The effects of BCGs on the statistics of large-separation lensed quasars by clusters     

Hong Qi  Da-Ming Chen National Astronomical Observatories  Chinese Academy of Sciences  Beijing  China 《中国天文和天体物理学报》2011,(9)

We study the statistics of large-separation multiply-imaged quasars lensed by clusters of galaxies.In particular,we examine how the observed brightest cluster galaxies (BCGs) affect the predicted numbers of wide-separation lenses.We model the lens as an NFW-profiled dark matter halo with a truncated singular isothermal sphere to represent the BCG in its center.We mainly make predictions for the Sloan Digital Sky Survey Quasar Lens Search (SQLS) sample from the Data Release 5 (DR5) in two standard ΛCDM cosmo...  相似文献   

The prediction method of similar cycles     

Zhan-Le Du  Hua-Ning Wang Key Laboratory of Solar Activity  National Astronomical Observatories  Chinese Academy of Sciences  Beijing  China 《中国天文和天体物理学报》2011,(12)

The concept of degree of similarity(η),is proposed to quantitatively describe the similarity of a parameter(e.g.the maximum amplitude Rmax)of a solar cycle relative to a referenced one,and the prediction method of similar cycles is further developed.For two parameters,the solar minimum(Rmin)and rising rate(βa),which can be directly measured a few months after the minimum,a synthesis degree of similarity(ηs)is defined as the weighted-average of theηvalues around Rmin and βa,with the weights given by the coef...  相似文献   

Lensing clusters of galaxies in the SDSS-Ⅲ     

Zhong-Lue Wen  Jin-Lin Han  Yun-Ying Jiang National Astronomical Observatories  Chinese Academy of Sciences  Beijing  China 《中国天文和天体物理学报》2011,(10)

We identify new strong lensing clusters of galaxies from the Sloan Digital Sky Survey III (SDSS DR8) by visually inspecting color images of a large sample of clusters of galaxies. We find 68 new clusters showing giant arcs in addition to 30 known lensing systems. Among 68 cases, 13 clusters are almost certain lensing systems with tangential giant arcs, 22 clusters are probable and 31 clusters are possible lensing systems. We also find two exotic systems with blue rings. The giant arcs have angular separatio...  相似文献   

The mini-QSO's contribution to cosmic reionization     

Ying-Ying Wang  Lei Wang  Shou-Ping Xiang  Yu Wang  Jing-Meng Hao  Ye-Fei Yuan Center for Astrophysics  University of Science  Technology of China  Hefei  China  Shanghai Astronomical Observatory  Joint Institute for Galaxy  Cosmologyof SHAO  USTC  Shanghai 《中国天文和天体物理学报》2010,10(3)

By employing an improved simulation of the evolution of black holes(BHs)based on the merger tree of dark matter halos,we explore the relationship between the central BH mass Mbh and velocity dispersion σflat high redshift z≥6 and quantify the mini-QSO's(with BH mass M=200-105M)contribution to cosmic reionization.The simulation demonstrates how seed BHs migrate onto the MBH-σ* relation by merging with each other and accreting gas at z≥6:1.The correlation between BHs and their host halos increases as the BHs ...  相似文献   

第十七批天文学名词的推荐译名     

中国天文学会天文学名词审定委员会 《天文学进展》2010,28(1)

中国天文学会名词审定委员会从1985年起开始在<天文学进展>发表天文学名词的推荐译名,到2009年已公布16批共2536个名词.现再推荐第17批114个名词,其中大多数是近年出现的天文学新词.希望读者在使用过程中对译名提出改进意见.  相似文献   

Interstellar Refractive Scintillation and Intraday Polarization Angle Swings     

A.Kraus 《中国天文和天体物理学报》2005,5(1):27-40

Intraday polarization angle swings of ~180° observed in two sources (QSO 0917+624 and QSO 1150+812) are discussed in the framework of refractive interstellar scintillation by a continuous interstellar medium. Model-fits to the I-, Q- and U- light curves were made for both sources. It is shown that for the case of 0917+624 both the intraday intensity variations and the polarization angle swing of ~180° could be explained consistently in  相似文献   

Resonant Heating of Ions by Parallel Propagating Alfvén Waves in Solar Coronal Holes     

Tian-Xi Zhang  Jing-Xiu Wang  Chi-Jie Xiao National Astronomical Observatories  Chinese Academy of Sciences  Beijing  Center for Space Plasma  Aeronomic Research  The University of Alabama in Huntsville  Huntsville  AL  USA   《中国天文和天体物理学报》2005,(3)

Resonant heating of H, O+5, and Mg+9 by parallel propagating ion cyclotron Alfven waves in solar coronal holes at a heliocentric distance is studied using the heating rate derived from the quasilinear theory. It is shown that the particle-AlfVen-wave interaction is a significant microscopic process. The temperatures of the ions are rapidly increased up to the observed order in only microseconds, which implies that simply inserting the quasilinear heating rate into the fluid/MHD energy equation to calculate the radial dependence of ion temperatures may cause errors as the time scales do not match. Different species ions are heated by Alfven waves with a power law spectrum in approximately a mass order. To heat O+5 over Mg+9 as measured by the Ultraviolet Coronagraph Spectrometer (UVCS) in the solar coronal hole at a region ≥1.9.R, the energy density of Alfven waves with a frequency close to the O+5-cyclotron frequency must be at least double of that at the Mg+9-cyclotron frequency. With an appropriate wa  相似文献   

The Relation between Tectonic Movement and Climatic Change     

Xuexiang Yang  Qiyuan Qiao  Dianyou Chen 《东北亚地学研究》2003,(1)

1SeesawphenomenonofoceaniccrustSince 1996, Yoshino etal.(2002) have been us-ing the space geodetic techniques to observe crustal deformation at four sites in Tokyo metropolitan area. It is called Keystone project (KSP). At the end of June in 2000, volcanic and seismic events star-ted at Izu islands, south of Tokyo. Following the ev-ent, extraordinary crustal deformation was observed not only around the Izu islands, but also at the Key-stone network, where the closest site is over 100…  相似文献   

The Kiloparsec-scale Structure of 3C 286     

Tao An  Xiao-Yu Hong  Wei-Hua WangShanghai Astronomical Observatory  Chinese Academy of Sciences  Shanghai  National Astronomical Observatories  Chinese Academy of Sciences  Beijing 《中国天文和天体物理学报》2004,4(1):28-36

We present radio images of the compact steep spectrum (CSS) quasar 3C 286 acquired with the Very Large Array (VLA) at 8.4 and 22.5 GHz. The source exhibits a two-sided core-jet structure with a bright central component and two extended components one to the east (P.A. 100°) and another to the southwest (P.A. - 116°). From the compact core, an extension runs towards the southwest component up to - 0.7 arcsecond. The emission between the primary central component and the southwest component exhibits a knotty structure. A gradual change of the jet position angles from -135° to -120° in the inner southwest jet suggests a local bend. The position angle changes of the major eastern components E2 and El suggest that the eastern jet likely follows a curved trace. The bends in the jet trace may be associated with a relativistic precession or some interaction between the jet and the ambient matter. A mean spectral index of a22.58.4 - -0.76 (Sv ∝ va) is estimated for the core component. Steep spectra are also  相似文献