ISSN:
1476-4687
Source:
Nature Archives 1869 - 2009
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Notes:
[Auszug] We have used two approximate methods to estimate the number of wide double images. The first works from the number density of rich clusters12 and the clustering of clusters3. There is no strong richness/velocity dispersion relation13'14 but we shall assume that two clusters of Abell richness class ...
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1038/323514a0