Non-Halo Structures and their Effects on Gravitational Lensing

Abstract

Anomalies in the flux-ratios of the images of quadruply-lensed quasars have been used to constrain the nature of dark matter. Assuming these lensing perturbations are caused by dark matter haloes, it is currently possible to constrain the mass of a hypothetical Warm Dark Matter (WDM) particle to be $m_{\chi }>5.2$ keV. However, the assumption that perturbations are only caused by DM haloes might not be correct as other structures, such as filaments and pancakes, exist and make up a significant fraction of the mass in the universe, ranging between 5$\%$ -- 50$\%$ depending on the dark matter model. Using novel fragmentation-free simulations of 1 and 3keV WDM cosmologies we study these "non-halo" structures and estimate their impact on flux-ratio observations. We find that these structures display sharp density gradients with short correlation lengths, and can contribute more to the lensing signal than all haloes up to the half-mode mass combined, thus reducing the differences expected among WDM models. We estimate that non-halo structures can be the dominant cause of line-of-sight flux-ratio anomalies in very warm, but already excluded, $m_x\sim 1\mathrm{keV}$ scenarios. For colder cases $m_x\gtrsim 3\mathrm{keV}$, we estimate that non-haloes can contribute about $5-10\%$ of the total flux-ratio signal.

arXiv comment14 pages, 10 figures. MNRAS submitted. Comments welcome

References in corpus (46)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The Structure of Cold Dark Matter Halos
• Axion Cosmology
• Dark Matter Search Results from a One Tonne$\times$Year Exposure of XENON1T
• How Filaments are Woven into the Cosmic Web
• Halo Formation in Warm Dark Matter Models
• Direct constraints on the dark matter self-interaction cross-section from the merging galaxy cluster 1E0657-56
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• Multi-scale initial conditions for cosmological simulations
• How supernova feedback turns dark matter cusps into cores
• Primordial Black Holes as Dark Matter: Recent Developments
• The persistent cosmic web and its filamentary structure I: Theory and implementation
• The properties of warm dark matter haloes
• Sterile Neutrino Dark Matter
• Axion Cosmology
• The Mass-Concentration-Redshift Relation of Cold and Warm Dark Matter Halos
• Baryons Matter: Why Luminous Satellite Galaxies Have Reduced Central Masses
• Nonlinear Evolution of Cosmological Structures in Warm Dark Matter Models
• Warm dark matter chills out: constraints on the halo mass function and the free-streaming length of dark matter with 8 quadruple-image strong gravitational lenses
• Discreteness effects in simulations of Hot/Warm dark matter
• Limits on spin-dependent WIMP-nucleon cross section obtained from the complete LUX exposure
• Lyman-alpha Forest Constraints on the Mass of Warm Dark Matter and the Shape of the Linear Power Spectrum
• Clumpy Streams from Clumpy Halos: Detecting Missing Satellites with Cold Stellar Structures
• SHARP -- VII. New constraints on the dark matter free-streaming properties and substructure abundance from gravitationally lensed quasars
• Tracing the Dark Matter Sheet in Phase Space
• Small-scale structure of fuzzy and axion-like dark matter
• The Warm DM halo mass function below the cut-off scale
• Pseudo Elliptical Lensing Mass Model: Application to the NFW Mass Distribution
• The COpernicus COmplexio: Statistical Properties of Warm Dark Matter Haloes
• Probing dark matter structure down to $10^7$ solar masses: flux ratio statistics in gravitational lenses with line of sight halos
• Joint constraints on thermal relic dark matter from strong gravitational lensing, the Lyman-$\alpha$ forest, and Milky Way satellites
• Subaru Mid-infrared Imaging of the Quadruple Lenses PG1115+080 and B1422+231: Limits on Substructure Lensing
• Constraining sterile neutrino cosmologies with strong gravitational lensing observations at redshift z~0.2
• Effects of baryon removal on the structure of dwarf spheroidal galaxies
• An adaptively refined phase-space element method for cosmological simulations and collisionless dynamics
• Probing the nature of dark matter particles with stellar streams
• The Birth and Growth of Neutralino Haloes
• ColDICE: a parallel Vlasov-Poisson solver using moving adaptive simplicial tessellation
• The core-cusp problem in cold dark matter halos and supernova feedback: Effects of Mass Loss
• Constraints on warm dark matter from weak lensing in anomalous quadruple lenses
• A Novel Approach to Visualizing Dark Matter Simulations
• Simulating the Complexity of the Dark Matter Sheet I: Numerical Algorithms
• Weak Lensing by Line-of-sight Halos as the Origin of Flux-ratio Anomalies in Quadruply Lensed QSOs
• Large-Scale Velocity Dispersion and the Cosmic Web
• Noiseless Gravitational Lensing Simulations
• Weak Lensing by Minifilament or Minivoid as the Origin of Flux-ratio Anomalies in Lensed Quasar MG0414+0534

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