Determination of the Large-Scale and Super-Large-Scale Structure by Means of the Space Distribution of Quasars

Quasars ◽  
1986 ◽  
pp. 495-496
Author(s):  
Y. Y. Zhou ◽  
D. P. Fang ◽  
Z. G. Deng ◽  
X. T. He
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Space Distribution

scholarly journals Determination of the large-scale and super-large-scale structure by means of the space distribution of quasars

1986 ◽  
Vol 119 ◽  
pp. 495-496
Author(s):  
Y.Y. Zhou ◽  
D.P. Fang ◽  
Z.G. Deng ◽  
X.T. He
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Space Distribution ◽  
The Universe

It is very important to study the large-scale structure by means of the space distribution of quasars. Using this method, one may search for the more distant superclusters and explore the super-large-scale structure, i.e., the existence of super-superclusters. The answer to the problem would be of great interest. It is related to the question about the transition of the clustering of galaxies on about 100 Mpc to the uniformity of the universe. Recently Oort et al and de Ruiter et al suggested that the quasars are located in superclusters. So we soppose that analysing the space distribution of quasars might give us some information about the super-large-scale structure of the universe. But up to the present the study of the clustering of quasars has not obtained universally accepted conclusions; in fact, some of them, including grouping and clustering (Arp; Chu and Zhu), no clustering (Chu and Zhu; Osmer; Webster), clustering for z < 2 and no clustering for z > 2 (Fang et al) and stringing (Deng et al), are contradictory.

scholarly journals Clusters of Galaxies

1980 ◽  
Vol 5 ◽  
pp. 699-714 ◽  
Author(s):  
Neta A. Bahcall
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Clusters Of Galaxies ◽  
Groups Of Galaxies ◽  
Formation And Evolution ◽  
The Rich ◽  
The Many ◽  
The Universe

AbstractClusters and groups of galaxies contain the majority of galaxies in the universe. The rich clusters, while less numerous than the many poor groups, are the densest and largest systems known, and can be easily recognized and studied even at relatively large distances. Their study is important for understanding the formation and evolution of clusters and galaxies, and for a determination of the large-scale structure in the universe.

scholarly journals A (2). Overall Structure: Space Distribution and Motions in the Disk

1955 ◽  
Vol 1 ◽  
pp. 13-24
Keyword(s):  
Large Scale ◽  
Galactic Plane ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Space Distribution ◽  
Interstellar Gas ◽  
Giant Stars ◽  
Galactic System ◽  
Wide Range ◽  
The Common

The population of the disk consists of a great variety of objects with a wide range of concentration towards the galactic plane and of peculiar motions. The extreme population I objects like interstellar gas and dust and super-giant stars, show quite different properties with respect to space distribution and motions, compared to such stars as, for instance, the common G and K giants. The discussions at the conference have concentrated on the observational possibilities of studying the correlation—or the lack of correlation—between the space distributions of different kinds of objects. From recent theoretical as well as observational work it has become apparent that there is a wide range in the ages of the stars contributing to the disk population, from a few million so some 1000 million years. The differences in the distributions of the various kinds of stars very probably must be interpreted in terms of these differences in age and evolution. The most intriguing problem for the present thus seems to be this: Can we trace large-scale structure in the distribution of objects of different ages, and can we derive information on the evolution of the galactic system and of the stars themselves from the degree of resemblance in the large-scale structure exhibited by different objects?

scholarly journals Automatic Three-Dimensional Measurement of Large-Scale Structure Based on Vision Metrology

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zhaokun Zhu ◽  
Banglei Guan ◽  
Xiaohu Zhang ◽  
Daokui Li ◽  
Qifeng Yu
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Blob Detection ◽  
Three Dimensional Measurement ◽  
Fully Automatic ◽  
Voting Strategy ◽  
Key Techniques

All relevant key techniques involved in photogrammetric vision metrology for fully automatic 3D measurement of large-scale structure are studied. A new kind of coded target consisting of circular retroreflective discs is designed, and corresponding detection and recognition algorithms based on blob detection and clustering are presented. Then a three-stage strategy starting with view clustering is proposed to achieve automatic network orientation. As for matching of noncoded targets, the concept of matching path is proposed, and matches for each noncoded target are found by determination of the optimal matching path, based on a novel voting strategy, among all possible ones. Experiments on a fixed keel of airship have been conducted to verify the effectiveness and measuring accuracy of the proposed methods.

scholarly journals Space Distribution of Radio-Source Populations

1996 ◽  
Vol 175 ◽  
pp. 547-552
Author(s):  
J.V. Wall
Keyword(s):  
Radio Source ◽  
Survey Data ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Space Distribution ◽  
Extragalactic Radio Source ◽  
The Status ◽  
Source Populations

This paper sets out the status of data determining the space distribution of extragalactic radio-source populations, describes some recent results from analyses of the data, and indicates why and how the analyses need revision in the light of unified models. It concludes by emphasizing the severity of the effects of large-scale structure on modern survey data.

Interplanetary Scintillation and Flare — Produced Disturbances

1975 ◽  
Vol 2 (6) ◽  
pp. 378-379 ◽  
Author(s):  
B.D. Ward
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Interplanetary Scintillation ◽  
Ensemble Averaging ◽  
Multiple Spacecraft ◽  
Spacecraft Data

Determination of the large-scale structure of flare-produced disturbances requires either multiple spacecraft observations or an ensemble averaging of single spacecraft observations of a number of events. There is currently some confusion in the results of studies of shock normals derived from spacecraft data. Chao and Lepping (1974) suggest that the average shock shape near 1 AU is essentially spherical while Bavassano et al. (1973) suggest that the disturbance corresponds closely to the shapes predicted in the numerical simulations of de Young and Hundhausen (1971).

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