2003/10/31 by Elena Torri, M. Meneghetti, Massimo Meneghetti +6 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07508.x
published as Mon.Not.Roy.Astron.Soc. 349 (2004) 476 · 16 pages, submitted to MNRAS, revised version after referee' Comments. Gzipped file including full resolution images can be downloaded at http://dipastro.pd.astro.it/~cosmo/massimo/high-res-images.tar.gz
arxiv created 2003/10/31 · openalex publication_date 2004/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the impact of merger events on the strong lensing properties of galaxy clusters. Previous lensing simulations were not able to resolve dynamical time-scales of cluster lenses, which arise on time-scales that are of the order of a Gyr. In this case study, we first describe qualitatively with an analytic model how some of the lensing properties of clusters are expected to change during merging events. We then analyse a numerically-simulated lens model for the variation in its efficiency for producing both tangential and radial arcs while a massive substructure falls on to the main cluster body. We find that: during the merger, the shape of the critical lines and caustics changes substantially; the lensing cross-sections for long and thin arcs can grow by one order of magnitude and reach their maxima when the extent of the critical curves is largest; the cross-section for radial arcs also grows, but the cluster can efficiently produce these kind of arcs only while the merging substructure crosses the main cluster centre, and while the arc cross-sections pass through their maxima as the merger proceeds, the X-ray emission of the cluster increases by a factor of ∼5.