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981.
Jing-Bo Wang Yu Gao Purple Mountain Observatory Chinese Academy of Sciences Nanjing China Graduate University of Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2010,10(4)
We present our initial results from a study of 14(U)LIRGs with a doublenucleus(z <0.15)and an AGN signature in the Chandra archive.The goals of our study are to search for more possible cases of binary AGNs and to investigate the X-ray properties and energy sources of these energetic objects,a major effort devoted specifically to searching for binary AGNs from(U)LIRGs.Our studies suggest that Mrk 266 might be a new candidate in hosting binary AGNs supported by X-ray observations.Our analysis shows that most(U)LIRGs are essentially weak X-ray sources and are not dominated by AGNs,due to both the lack of Fe K line detections and weak emission in the hard X-ray band.We find evidence for thermal emission with temperature kT~0.7 keV in seven nuclear regions,and this component is possibly associated with the nuclear or circumnuclear starburst.The soft and hard X-ray to far-infrared ratios also suggest that most(U)LIRGs are not energetically dominated by AGNs.Therefore,this study only provides one additional candidate of binary AGNs.We cannot rule out the existence of low luminosity AGNs and thus binary AGNs in all of them,particulaxly,those highly obscured and spatially unresolved systems.Nine of 14(U)LIRGs,including three previously known binary AGNs and a new candidate Mrk 266,clearly have obvious X-ray counterparts to their double optical/near-IR nuclei,whereas only two out of 14 have one obvious X-ray counterpart detected.Additionally,Arp 220 and Mrk 273 are not spatially resolved owing to their small nuclear separations(~1"),and no significant X-ray detection in the most distant source. 相似文献
982.
Yi-Nan Zhu Hong Wu Hai-Ning Li Chen Cao National Astronomical Observatories Chinese Academy of Sciences Beijing China of Sciences China Graduate University of Chinese Academy of Sciences Beijing China Institute of Space Science Physics Sh ong University at Weihai Sh ong 《中国天文和天体物理学报》2010,10(4)
We analyze the feasibility of estimating the stellar mass of galaxies by mid-infrared luminosities based on a large sample of galaxies cross-identified from Spitzer SWIRE fields and the SDSS spectrographic survey.We derived the formulae to calculate the stellar mass by using IRAC 3.6 μm and 4.5 μm luminosities.The massto-luminosity ratios of IRAC 3.6 μm and 4.5 μm luminosities are more sensitive to the star formation history of galaxies than to other factors,such as the intrinsic extinction,metallicity and star formation rate.To remove the effect of star formation history,we used g-r color to recalibrate the formulae and obtain a better result.Researchers must be more careful when estimating the stellar mass of low metallicity galaxies using our formulae.Due to the emission from dust heated by the hottest young stars,luminous infrared galaxies present higher IRAC 4.5 μm luminosities compared to IRAC 3.6 μm luminosities.For most of type-Ⅱ AGNs,the nuclear activity cannot enhance 3.6 μm and 4.5 μm luminosities compared with normal galaxies.Star formation in our AGNhosting galaxies is also very weak,almost all of which are early-type galaxies. 相似文献
983.
984.
The Radioheliograph Group 《Solar physics》1989,120(1):193-204
A multi-frequency capability has been added to the north-south array of the Nançay Radioheliograph, providing observations at up to five frequencies between 150 and 450 MHz with time resolution 0.1 s. The projected position, brightness and dimension of sources in the solar corona can thus be studied as a function of height. Two-dimensional information is obtained at 164 MHz using the east-west and north-south arrays. In addition, the quiescent corona can be mapped in two dimensions at all observed frequencies by earth rotation synthesis. The paper describes the new aspects of the antennae, the receiver frontend, the data acquisition and the calibration procedure. The performances of the instrument are illustrated with multi-frequency observations of solar fast-drift bursts, continuum emission and maps of the quiet corona.Meudon: Y. Avignon, J. Bonmartin, A. Bouteille, B. Clavelier, E. Hulot, M. P. Issartel, A. Kerdraon, K.-L. Klein, P. Lantos, C. Mercier, M. Pick, A. Raoult, D. Rigaud, G. Trottet, N. Vilmer. Nançay: C. Chantelat, M. Chapuis, Y. Chapuis, A. Coffre, C. Couteret, B. Darchy, P. Guéniau, D. Lalardie, P. Picard, R. Tocqueville. 相似文献
985.
辽北凡河地区雾迷山期火山岩可划分为海相火山熔岩与次火山岩,受基底断裂构造控制,遭受与围岩同步的褶皱变形。海相火山熔岩主要为细碧岩、蚀变玄武岩;次火山岩主要为次蚀变辉绿岩、熔岩状次蚀变辉绿岩,两者具有相似的稀土丰度及稀土分馏特征。凡河地区火山岩形成于大陆克拉通内的活动带,即裂陷槽强烈活动阶段的产物。 相似文献
986.
HUANG Yongwei LIU Jiajun QUAN Chuanshun ZHU Wenfeng . First Institute of Geology Exploration of Heilongjiang Province Mudanjiang Heilongjiang China . School of Earth Sciences Resources China University of Geosciences Beijing . Sh ong Geologic Surveying Mapping Institute Jinan 《东北亚地学研究》2011,(2)
Sipingshan gold deposit is gold-bearing sillcalite in type. There only exist a few kinds of sulfide in the ore and it is lower in content. The gold degree is lower. Au is closely related to the Ag,Cu,Pb,As and Hg elements. The upper sillcalite has Eu and Ce negative anomaly,and the lower sillcalite has Eu positive anomaly. however,the hot spring cemented breccia and rhyolite porphyry have Eu negative anomaly;the S isotope component has deep-seated magmatic sulfur and terrestrial sulfate characteristic;and t... 相似文献
987.
3维离散数据四面体快速生成算法研究 总被引:6,自引:2,他引:6
文中系统地研究了使用逐点插入算法构建3维离散数据四面体模型中的几个关键问题,提出了动态创建和维护四面体拓扑关系的方法,建立了快速确定点在四面体中的算法原理及空外接球判断法则的简易表达式,实验分析证明本算法有着较高的执行效率,算法复杂度与点数几乎成线性关系。 相似文献
988.
989.
The experimental studies of the wave breaking effects on freak wave generation are presented within a finite-depth random wave train in a laboratory wave tank. The main attention is paid to the abnormal index,AI=Hmax/Hs,being used to characterize the freak waves,and the changes of the coefficient due to wave breaking. The results show that the occurrence probability of freak wave events in non-breaking waves is much larger than that in breaking waves and such occurrence in deep water is larger than that in ... 相似文献
990.