Volume 569, September 2014
|Number of page(s)||9|
|Section||Cosmology (including clusters of galaxies)|
|Published online||15 September 2014|
The strongest gravitational lenses
IV. The order statistics of the largest Einstein radii with cluster mergers
Zentrum für Astronomie der Universität Heidelberg, Institut für
2 Blue Yonder GmbH, Ohiostrasse 8, 76149 Karlsruhe, Germany
Accepted: 7 August 2014
Based on techniques developed in the previous papers of this series, we investigate the impact of galaxy-cluster mergers on the order statistics of the largest Einstein radii. We show that the inclusion of mergers significantly shifts the extreme value distribution of the largest Einstein radius to higher values, typically increasing the expected value by ~10%. A comparison with current data reveals that the largest observed Einstein radius agrees excellently well with the theoretical predictions of the ΛCDM model at redshifts z > 0.5. At redshifts z < 0.5, our results are somewhat more controversial. Although cluster mergers also increase the expected values of the order statistics of the n largest Einstein radii by ~10%, the theoretically expected values are notably lower (~3σ deviation for n = 12) than the largest Einstein radii of a selected sample of SDSS clusters in the redshift range 0.1 ≤ z ≤ 0.55. The uncertainties of the observed Einstein radii are still large, however, and thus the measurements need to be carefully revised in future works. Therefore, given the premature state of current observational data, overall, there is still no reliable statistical evidence for observed Einstein radii to exceed the theoretical expectations of the standard cosmological model.
Key words: cosmology: theory / gravitational lensing: strong / galaxies: clusters: general / methods: statistical
© ESO, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.