Galaxy-galaxy strong lensing cross-section with fuzzy dark matter model

TL;DR

This paper investigates how fuzzy dark matter models affect galaxy-galaxy strong lensing cross-sections, finding that while FDM can increase cross-sections compared to CDM, it may still fall short of observed values.

Contribution

The study provides a numerical and analytical analysis of FDM's impact on GGSL cross-sections, highlighting the role of soliton cores and baryon distribution.

Findings

FDM subhalos can produce larger cross-sections than CDM due to soliton cores.

Maximum cross-section occurs when core radius matches critical curve size.

FDM with any mass may not fully explain the observed GGSL cross-section.

Abstract

The galaxy-galaxy strong lensing (GGSL) cross-section in observed galaxy clusters has been reported to be more than an order of magnitude higher than the theoretical prediction by the standard cold dark matter (CDM) model. In this study, we focus on the fuzzy dark matter (FDM) model and study the GGSL cross-section numerically and analytically. We find that FDM subhalos can produce larger cross-sections than the CDM subhalos due to the presence of the soliton core. The maximum cross-section is obtained when the core radius is about the same as the size of the critical curve. The peak ratio of the cross-sections between the FDM subhalos and the CDM subhalos is about two when including the baryon distribution, indicating that the FDM with any masses might not produce the expected observed cross-section.