Harnessing stellar kinematics to constrain dark energy with the double-source-plane gravitational lens SDSS J0946+1006
Abstract
SDSS J0946+1006 is an attractive target for measuring cosmological parameters through lens modelling. It is the best-studied galaxy-scale strong gravitational lens with multiple sources whose redshift separations are well-suited to constraining the dark energy equation of state. However, multi-plane lens models with free cosmological parameters risk a multi-plane mass-sheet degeneracy, although this can be lifted by a non-lensing deflector density profile tracer. We simultaneously reconstruct near-infrared and near-ultraviolet HST imaging whilst including a velocity dispersion measurement from VLT-MUSE to constrain the foreground deflector. Imaging is reconstructed faithfully regardless of whether the inferred kinematics are realistic, though we find the kinematic constraint essential for shifting the preferred cosmology into a region not in significant tension with other dark energy probes. Deflector density profile perturbations, via substructure and multipolar halo shape deformations, have only a modest effect on inferred cosmology. Combining our fiducial model with Planck CMB data yields w=−1.01+0.08−0.13; or, combined with Pantheon SNe Ia, w=−0.99+0.13−0.15. We further show that this system proves a remarkably valuable complementary probe in the w0-wa plane of an evolving dark energy model, and that the DESI BAO tension with ΛCDM seen when combined with other datasets is not reproduced when combined with this lens, yielding (w0, wa)=(−0.87+0.10−0.11, −0.22+0.28−0.25). The system's third source, visible with MUSE, only weakly constrains wCDM but may strengthen w0waCDM constraints, though further mass-model complexity along its line of sight is required. Overall, kinematics-informed multi-plane lens modelling is a robust route to competitive dark energy constraints, even with a single system.
Related
- Strong Lensing Tomography: Double and pseudo multi-source plane strong gravitational lensing to constrain dark energy
- A MUSE study of stellar and ionized-gas kinematics in central group galaxies
- How tightly can PBH abundance information constrain scalar-induced gravitational waves?
- Stellar Kinematics and Molecular Gas toward NGC 6357: An Overlooked Earlier Stellar Generation
- Gaia DR3 Reveals the Kinematics of Young Stellar Objects in the Carina Nebula: Peripheral Expansion and Central Rotation
BibTeX
@misc{ballard2026harnessing,
title = {{Harnessing stellar kinematics to constrain dark energy with the double-source-plane gravitational lens SDSS J0946+1006}},
author = {Daniel J. Ballard and Wolfgang J. R. Enzi and Thomas E. Collett and Coleman M. Krawczyk and Giovanni Granata and Tian Li and Geraint F. Lewis and Karl Glazebrook and Huimin Qu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.08573},
eprint = {2609.08573},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.08573},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Harnessing stellar kinematics to constrain dark energy with the double-source-plane gravitational lens SDSS J0946+1006
AU - Daniel J. Ballard
AU - Wolfgang J. R. Enzi
AU - Thomas E. Collett
AU - Coleman M. Krawczyk
AU - Giovanni Granata
AU - Tian Li
AU - Geraint F. Lewis
AU - Karl Glazebrook
AU - Huimin Qu
PY - 2026
DA - 2026/09/08
PB - arXiv
DO - 10.48550/arxiv.2609.08573
UR - https://arxiv.org/abs/2609.08573
AB - SDSS J0946+1006 is an attractive target for measuring cosmological parameters through lens modelling. It is the best-studied galaxy-scale strong gravitational lens with multiple sources whose redshift separations are well-suited to constraining the dark energy equation of state. However, multi-plane lens models with free cosmological parameters risk a multi-plane mass-sheet degeneracy, although this can be lifted by a non-lensing deflector density profile tracer. We simultaneously reconstruct near-infrared and near-ultraviolet HST imaging whilst including a velocity dispersion measurement from VLT-MUSE to constrain the foreground deflector. Imaging is reconstructed faithfully regardless of whether the inferred kinematics are realistic, though we find the kinematic constraint essential for shifting the preferred cosmology into a region not in significant tension with other dark energy probes. Deflector density profile perturbations, via substructure and multipolar halo shape deformations, have only a modest effect on inferred cosmology. Combining our fiducial model with Planck CMB data yields w=−1.01^+0.08_−0.13; or, combined with Pantheon SNe Ia, w=−0.99^+0.13_−0.15. We further show that this system proves a remarkably valuable complementary probe in the w_0-w_a plane of an evolving dark energy model, and that the DESI BAO tension with ΛCDM seen when combined with other datasets is not reproduced when combined with this lens, yielding (w_0, w_a)=(−0.87^+0.10_−0.11, −0.22^+0.28_−0.25). The system's third source, visible with MUSE, only weakly constrains wCDM but may strengthen w_0w_aCDM constraints, though further mass-model complexity along its line of sight is required. Overall, kinematics-informed multi-plane lens modelling is a robust route to competitive dark energy constraints, even with a single system.
ER -