Weak lensing detection of intra-cluster filaments with ground based data

TL;DR

This paper presents two novel gravitational lensing methods tailored for ground-based data to detect and map the elusive filamentary structures of the cosmic web, demonstrating their effectiveness through realistic simulations.

Contribution

It introduces two specific methods for detecting intra-cluster filaments via weak lensing, optimized for ground-based observations, and validates their feasibility with N-Body simulation data.

Findings

Detection of filaments with ppa rom 0.005 to 0.01

Filament detection feasible with ground-based data

Methods outperform previous approaches in sensitivity

Abstract

According to the current standard model of Cosmology, matter in the Universe arranges itself along a network of filamentary structure. These filaments connect the main nodes of this so-called 'Cosmic Web', which are clusters of galaxies. Although its large-scale distribution is clearly characterized by numerical simulations, constraining the dark matter content of the cosmic web in reality turns out to be difficult. The natural method of choice is gravitational lensing. However, the direct detection and mapping of the elusive filament signal is challenging and in this work we present two methods,specifically tailored to achieve this task. A linear matched filter aims at the detection of the smooth mass component of filaments and is optimized to perform a shear decomposition that follows the anisotropic component of the lensing signal. Filaments clearly inherit this property due to their morphology. At the same time, the contamination arising from the central massive cluster is controlled in a natural way. The filament 1 {\sigma} detection is of about {\kappa} ~ 0.01-0.005 according to the filter's template width and length, enabling the detection of structures out of reach with other approaches. The second, complementary method seeks to detect the clumpy component of filaments. The detection is determined by the number density of sub-clump identifications in an area enclosing the potential filament, as it was found within the observed field with the filter approach. We test both methods against Mock observations based on realistic N-Body simulations of filamentary structure and prove the feasibility of detecting filaments with ground-based data.