Flux-limited strong gravitational lensing and dark energy

Free access article

Issue		A&A Volume 418, Number 2, May I 2004


Page(s)		387 - 392
Section		Cosmology (including clusters of galaxies)
DOI		http://dx.doi.org/10.1051/0004-6361:20040049

A&A 418, 387-392 (2004)
DOI: 10.1051/0004-6361:20040049

Flux-limited strong gravitational lensing and dark energy

D.-M. Chen

National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China
(Received 23 June 2003 / Accepted 15 January 2004 )

Abstract
In the standard flat cosmological constant ( $\Lambda$ ) cold dark matter (CDM) cosmology, a model of two populations of lens halos for strong gravitational lensing can reproduce the results of the Jodrell-Bank VLA Astrometric Survey (JVAS) and the Cosmic Lens All-Sky Survey (CLASS) radio survey. In such a model, lensing probabilities are sensitive to three parameters: the concentration parameter c₁, the cooling mass scale $M_{\rm c}$ and the value of the CDM power spectrum normalization parameter $\sigma_8$ . The value ranges of these parameters are constrained by various observations. However, we found that predicted lensing probabilities are also quite sensitive to the flux density (brightness) ratio $q_{{\rm r}}$ of the multiple lensing images, which has been a very important selection criterion of a sample in any lensing survey experiments. We re-examine the mentioned above model by considering the flux ratio and galactic central Super Massive Black Holes (SMBHs), in flat, low-density cosmological models with different cosmic equations of state $\omega$ , and find that the predicted lensing probabilities without considering $q_{{\rm r}}$ are over-estimated. A low value of $q_{{\rm r}}$ can be compensated for by raising the cooling mass scale $M_{\rm c}$ in fitting the predicted lensing probabilities to JVAS/CLASS observations. To determine the cosmic equation of state $\omega$ , the uncertainty in $M_{\rm c}$ must be resolved. The effects of SMBHs cannot be detected by strong gravitational lensing methods when $q_{{\rm r}}\leq 10$ .

Key words: cosmology: theory -- cosmology: gravitational lensing

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.