EDP Sciences
Free access
Issue
A&A
Volume 409, Number 2, October II 2003
Page(s) 449 - 457
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20031158


A&A 409, 449-457 (2003)
DOI: 10.1051/0004-6361:20031158

Arc statistics in cosmological models with dark energy

M. Bartelmann1, M. Meneghetti1, 2, F. Perrotta3, 4, 5, C. Baccigalupi4, 5 and L. Moscardini6

1  Max-Planck-Institut für Astrophysik, PO Box 1317, 85741 Garching, Germany
2  Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 2, 35122 Padova, Italy
3  Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy
4  Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
5  SISSA/ISAS, via Beirut 4, 34014 Trieste, Italy
6  Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy

(Received 2 October 2002 / Accepted 18 July 2003)

Abstract
We investigate how the probability of the formation of giant arcs in galaxy clusters is expected to change in cosmological models dominated by dark energy with an equation of state $p=w\rho c^2$ compared to cosmological-constant or open models. To do so, we use a simple analytic model for arc cross sections based on the Navarro-Frenk-White density profile which we demonstrate reproduces essential features of numerically determined arc cross sections. Since analytic lens models are known to be inadequate for accurate absolute quantifications of arc probabilities, we use them only for studying changes relative to cosmological-constant models. Our main results are (1) the order of magnitude difference between the arc probabilities in low density, spatially flat and open CDM models found numerically is reproduced by our analytic model, and (2) dark-energy cosmologies with w>-1 increase the arc optical depth by at most a factor of two and are thus unlikely to reconcile arc statistics with spatially flat cosmological models with low matter density.


Key words: galaxies: clusters: general -- cosmology: theory -- cosmology: dark matter -- cosmology: gravitational lensing

Offprint request: M. Bartelmann, msb@mpa-garching.mpg.de




© ESO 2003

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.