|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'585
Articles rated: 2609
24 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Is the Number of Giant Arcs in LCDM Consistent With Observations? | | G.L. Li
; S. Mao
; Y.P. Jing
; M. Bartelmann
; X. Kang
; M. Meneghetti
; | | Date: |
8 Mar 2005 | | Subject: | astro-ph | | Abstract: | We use high-resolution N-body simulations to study the galaxy-cluster cross-sections and the abundance of giant arcs in the $Lambda$CDM model. Clusters are selected from the simulations using the friends-of-friends method, and their cross-sections for forming giant arcs are analyzed. The background sources are assumed to follow a uniform ellipticity distribution from 0 to 0.5 and to have an area identical to a circular source with diameter $1arcsec$. We find that the optical depth scales as the source redshift approximately as $ au_{1’’} = 2.25 imes 10^{-6}/[1+(zs/3.14)^{-3.42}]$ ($0.63$. The optical depth is sensitive to the source redshift, in qualitative agreement with Wambsganss et al. (2004). However, our overall optical depth appears to be only $sim$ 10% to 70% of those from previous studies. The differences can be mostly explained by different power spectrum normalizations ($sigma_8$) used and different ways of determining the $L/W$ ratio. Finite source size and ellipticity have modest effects on the optical depth. We also found that the number of highly magnified (with magnification $|mu|>10$) and ``undistorted’’ images (with $L/W<3$) is comparable to the number of giant arcs with $|mu|>10$ and $L/W>10$. We conclude that our predicted rate of giant arcs may be lower than the observed rate, although the precise `discrepancy’ is still unclear due to uncertainties both in theory and observations. | | Source: | arXiv, astro-ph/0503172 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER