The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters

Robertson, Andrew

Abstract

We investigate a recent claim that observed galaxy clusters produce an order of magnitude more galaxy–galaxy strong lensing (GGSL) than simulated clusters in a Λ cold dark matter (CDM) cosmology. We take galaxy clusters from the C-EAGLE hydrodynamical simulations and calculate the expected amount of GGSL for sources placed behind the clusters at different redshifts. The probability of a source lensed by one of the most massive C-EAGLE clusters being multiply imaged by an individual cluster member is in good agreement with that inferred for observed clusters. We show that numerically converged results for the GGSL probability require higher resolution simulations than had been used previously. On top of this, different galaxy formation models predict cluster substructures with different central densities, such that the GGSL probabilities in ΛCDM cannot yet be robustly predicted. Overall, we find that GGSL within clusters is not currently in tension with the ΛCDM cosmological model.

Citation

Robertson, A. (2021). The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters. Monthly Notices of the Royal Astronomical Society: Letters, 504(1), L7-L11. https://doi.org/10.1093/mnrasl/slab028

• Journal Article Type: Article
• Acceptance Date: Mar 15, 2021
• Online Publication Date: Mar 22, 2021
• Publication Date: 2021-06
• Deposit Date: Nov 16, 2021
• Publicly Available Date: Nov 16, 2021
• Journal: Monthly Notices of the Royal Astronomical Society: Letters
• Electronic ISSN: 1745-3933
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 504
• Issue: 1
• Pages: L7-L11
• DOI: https://doi.org/10.1093/mnrasl/slab028
• Public URL: https://durham-repository.worktribe.com/output/1221729