Measuring the Stellar-to-Halo Mass Relation at $\sim 10^{10}$ Solar masses, using forthcoming space-based imaging of galaxy-galaxy strong lenses

Abstract

The stellar-to-halo mass relation (SHMR) is central to understanding the co-evolution of galaxies and their host dark matter haloes, yet it remains weakly constrained for dwarf galaxies owing to their faintness, especially beyond the Local Group. Strong gravitational lensing offers a unique probe of the SHMR at sub-galactic scales and cosmological distances, as the masses of subhalos within the main lens can be inferred from the perturbations they imprint on lensed images. Anticipating the discovery of $\sim 10^5$ galaxy--galaxy strong lenses by forthcoming facilities such as \textit{Euclid}, we perform an end-to-end simulation to forecast \textit{Euclid}'s constraints on the SHMR at the halo mass scale of $\sim 10^{10}{\mathrm{M}}_{\odot }$. We generate mock \textit{Euclid} VIS images of lens systems hosting a fiducial $3\times 10^{10}{\mathrm{M}}_{\odot }$ subhalo and vary its properties to assess the robustness of mass inference. We find that \textit{Euclid}'s angular resolution cannot break the intrinsic mass--concentration degeneracy of subhaloes, nor deblend the light of satellite galaxies (when present) associated with them, leading to biased inferred halo masses. These limitations are overcome with high-resolution follow-up imaging from facilities such as the \textit{Hubble Space Telescope}, enabling accurate halo-mass measurements. We forecast that a statistical sample of $\sim 100$ such systems, combining lensing-derived halo masses with stellar masses from photometric SED fitting, can constrain the SHMR at dwarf-galaxy scales with a precision of $\sim 0.05$~dex in halo mass and $\sim 0.03$~dex in stellar mass, enabling powerful tests of galaxy formation theories.

11 pages, 9 figures, published in MNRAS

References in corpus (19)

• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• Euclid. I. Overview of the Euclid mission
• The Sloan Lens ACS Survey. V. The Full ACS Strong-Lens Sample
• Dark matter and cosmic structure
• Bayesian Strong Gravitational-Lens Modeling on Adaptive Grids: Objective Detection of Mass Substructure in Galaxies
• Composable Effects for Flexible and Accelerated Probabilistic Programming in NumPyro
• COSMOS2020: The Galaxy Stellar Mass Function: the assembly and star formation cessation of galaxies at $0.2<z\le 7.5$
• PyAutoLens: Open-Source Strong Gravitational Lensing
• Euclid Preparation IV. Impact of undetected galaxies on weak-lensing shear measurements
• Introduction to the Chinese Space Station Survey Telescope (CSST)
• Automated galaxy-galaxy strong lens modelling: no lens left behind
• Globular clusters as tracers of the dark matter halo: insights from the E-MOSAICS simulations
• Gravitational imaging through a triple source plane lens: revisiting the $\Lambda$CDM-defying dark subhalo in SDSSJ0946+1006
• Sensitivity of strong lensing observations to dark matter substructure: a case study with Euclid
• Testing strong lensing subhalo detection with a cosmological simulation
• Systematic errors induced by the elliptical power-law model in galaxy-galaxy strong lens modeling
• Self-consistent Color-Mass-to-Light-Ratio relations for Low Surface Brightness Galaxies
• Detecting low-mass haloes with strong gravitational lensing II: constraints on the density profiles of two detected subhaloes
• Impacts of source morphology on the detectability of subhalos in strong lenses

Cited by in corpus (1)

• Using Strong Lensing to Detect Subhalos with Steep Inner Density Profiles