Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method

Details Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method

1998-12-21

arxiv.org/abs/astro-ph/9812388v1

Astronomy and Astrophysics

Astrophysics

Submitted to Astronomy & Astrophysics. Latex and l-aa.sty. 15 pages, 9 figures, 505 Kb

Scientific paper

We present a new geometrical method which uses weak gravitational lensing effects in clusters to constrain the cosmological parameters Omega and Lambda. On each background galaxy, a cluster induces a convergence and a shear terms, which depend on the cluster projected potential, and on the cosmological parameters (Omega,Lambda), through the angular distance ratio D_{LS}/D_{OS}. To disentangle the effects of these three quantities, we compare the relative values of the ellipticities for each triplet of galaxies located at about the same position in the lens plane, but having different color redshifts. The simultaneous knowledge of the ellipticities and photometric redshifts enable to build a purely geometrical estimator of (Omega,Lambda) which does not depend on the lens potential.A calculation and comparison of each source of statistical noise is performed. We also analyzed the systematics.Simulations lead to encouraging constraints on the curvature of the Universe and can discriminate an open from a flat Universe. The test can also provide constraints on Lambda. By using 20 VLT nights to observe 100 clusters, we can reach Lambda_{-0.2}^{+0.3} for \Omega+\Lambda=1, or Omega_{-0.25}^{+0.3} for \Lambda=0. The method is even better adapted to a large program on the NGST.

Affiliated with

Also associated with

No associations

Rating

Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraining $(Ω,Λ)$ from weak lensing in clusters: the triplet method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-483408