H_2CO and H110α survey toward UCHII regions     

Jarken Esimbek 《中国天文和天体物理学报》2011,(2)

We report results of the H2CO and H110α survey toward 281 UCHII regions using the Urumqi 25m radio telescope.We obtained 37 new H2CO detections,and H110α was simultaneously detected in eight of them.Only H110α was detected in another UCHII region.We calculated kinematic distances of nine UCHII regions with the detected H110α and resolved the kinematic distance ambiguity for six of them.The detection rate of H2CO of our observation was 13.2%,which is low compared with one of the other authors.The possible re...  相似文献   

Origin of power-law X-ray emission in the steep power-law state of X-ray binaries     

Li-Hong Yan  Jian-Cheng Wang Yunnan Observatory /National Astronomical Observatories  Key Laboratory for the Structure  Evolution of Celestial Objects  Chinese Academy of Sciences  Kunming  China Graduate School of Chinese Academy of Sciences  Beijing  China 《中国天文和天体物理学报》2011,(6)

We present a new explanation for the origin of the steep power-law(SPL) state of X-ray binaries.The power-law component of X-ray emission is the synchrotron radiation of relativistic electrons in highly magnetized compact spots orbiting near the inner stable circular orbit of a black hole.It has a hard spectrum that extends to above MeV energies,which is determined by the electron acceleration rate.These photons are then down-scattered by the surrounding plasma to form an observed steep spectrum.We discuss ...  相似文献   

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 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   

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   

A Photometric Study of the W UMa-type Eclipsing Binary System GSC 0445-1993     

M.D.Koppelman 《中国天文和天体物理学报》2005,5(2):137-143

Several new light minimum times for the eclipsing binary GSC 0445-1993 have been determined from the observations by Koppelman et al. and the orbital period of this system was revised. A photometric analysis was carried out using the 2003 version of the Wilson-Devinney code. The results reveal that GSC 0445-1993 is a W-type eclipsing binary with a mass ratio of q = 0.323(±0.002) and an over-contact degree of f = 22.8%(±4.2%). A small temperature difference between the components of △T = 135 K and an orbital inclination of i = 65.7°(±0.3°) were obtained. The asymmetry of its light curve (i.e., the O'Connell effect) for this binary star is explained by the presence of a dark spot on the more massive component.  相似文献   

Integrated Futures for Europe’s Mountain Regions: Reconciling Biodiversity Conservation and Human Livelihoods   总被引：1，自引：1，他引：0  

Jonathan Mitchley  Martin F.Price  Joseph Tzanopoulos 《山地科学学报》2006,(4)

Introduction Europe's mountains cover nearly half of the continent's area (Price et al. 2004) and land cover varies significantly (European Commission 2004). In most massifs, except for Sicily, southern Greece, and the British Isles, forest cover is dominant. In northern Europe, grassland is proportionately more important, and much of the mountains of the British Isles is covered by moorland. In central and southern Europe, arable land is of far greater importance than grassland, with Med…  相似文献   

Elementary analysis of data from Tianchi Volcano     

LIUGuo-ming ZHANGHeng-rong KONGQing-jun WUCheng-zhi GUOFeng ZHANGChao-fan 《东北亚地学研究》2004,7(2):156-160

Tianchi Volcano is the largest potential erupticve volcano in China. Analyzing these data on seismic monitoring, deformation observation and water chemistry investigation gained from the Tianchi Volcano Observatory (TVO), the authors consider that the Tianchi Volcano is in going into a new flourishing time.  相似文献   

云南天文台对流星的视频观测     

吴光节  张周生 《天文学报》2004,45(2):186-194

近20年来，随着CCD和像增强器的发展，小巧灵活的流星视频观测系统在世界上逐渐多了起来．并且，最终将可能逐步取代流星的目视观测和普通照相观测．介绍云南天文台I号流星彗星视频照相系统的研制及其初步观测结果．这一系统由容易转换的5组件构成．用于流星观测的大视场相机的视场约36度，单帧图像可观测到约6等恒星．实测的恒星星等测量精度可达约0.2等．还讨论了视频照相机比传统的感光胶卷照相的长处，以及视频照相系统的改进与发展．  相似文献