Narrowing down the Hubble constant value by exploiting the extended surface brightness of the supernova Refsdal host galaxy
Abstract
We present the first inference of the Hubble constant and matter density parameter from a strongly lensed supernova by exploiting the mass model of a galaxy cluster enhanced by an extended surface brightness reconstruction. Building upon the recent mass model of the galaxy cluster MACS J1149.5+2223, relying on the identified image positions only, we include the surface brightness distribution of the SN Refsdal host, to infer some cosmological parameter values within a flat LCDM framework. We consider two cosmological parameterizations, with either H0 and Ωm or H0 alone treated as free parameters, acknowledging the milder dependency on Ωm when incorporating additional constraints from the SN host. We explore four different mass-model realizations to assess some of the systematic uncertainties associated with the constraint weighting and source reconstruction. Although known as one of the main possible systematic effects, including influences from the external convergence, we deliberately keep the cluster total mass parametrization fixed to that of the previously published point-like mass model to enable a fair comparison. This reveals that incorporating 77,000 HST pixels reduces the uncertainty on the inferred value of the Hubble constant by a factor of 2.0, while all model realizations remain mutually consistent. Our final measurements are H0 = 65.0+2.0−1.8 km/s/Mpc and $Ω_m = 0.30^{+0.08}_{-0.09}, in agreement with previous results. This corresponds to a substantially improved precision, reaching a remarkable 3.0% uncertainty on the value of H0 given our cluster total mass parameterization. The contributions of the uncertainties on the lens total mass and on the measured time delays to the final H0 error are now comparable, indicating that future improvements in cluster-scale time-delay cosmography will increasingly depend on (abridged version).
Related
- Fermi-LAT Detection of Extended GeV Emission toward the Middle-aged Supernova Remnant G156.2+05.7
- Parameterizations of the Hubble Constant from the Binned Type Ia Supernova Master Sample: Logarithmic versus Power-law Forms
- Extended gamma-ray emission in the vicinity of the Westerlund 1 massive star cluster and Kes 41 supernova remnant seen by the Fermi Large Area Telescope
- The connection between surface brightness and satellite systems for central galaxies through IllustrisTNG (Corrigendum)
- CHEX-MATE: X-ray surface brightness discontinuities across a representative cluster sample
BibTeX
@misc{schuldt2026narrowing,
title = {{Narrowing down the Hubble constant value by exploiting the extended surface brightness of the supernova Refsdal host galaxy}},
author = {S. Schuldt and C. Grillo and S. H. Suyu and A. Acebron and L. Bazzanini and P. Bergamini and G. Di Rosa and A. Halkola and A. Mercurio and P. Rosati},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.12595},
eprint = {2610.12595},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.12595},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Narrowing down the Hubble constant value by exploiting the extended surface brightness of the supernova Refsdal host galaxy
AU - S. Schuldt
AU - C. Grillo
AU - S. H. Suyu
AU - A. Acebron
AU - L. Bazzanini
AU - P. Bergamini
AU - G. Di Rosa
AU - A. Halkola
AU - A. Mercurio
AU - P. Rosati
PY - 2026
DA - 2026/10/13
PB - arXiv
DO - 10.48550/arxiv.2610.12595
UR - https://arxiv.org/abs/2610.12595
AB - We present the first inference of the Hubble constant and matter density parameter from a strongly lensed supernova by exploiting the mass model of a galaxy cluster enhanced by an extended surface brightness reconstruction. Building upon the recent mass model of the galaxy cluster MACS J1149.5+2223, relying on the identified image positions only, we include the surface brightness distribution of the SN Refsdal host, to infer some cosmological parameter values within a flat LCDM framework. We consider two cosmological parameterizations, with either H0 and Ωm or H0 alone treated as free parameters, acknowledging the milder dependency on Ωm when incorporating additional constraints from the SN host. We explore four different mass-model realizations to assess some of the systematic uncertainties associated with the constraint weighting and source reconstruction. Although known as one of the main possible systematic effects, including influences from the external convergence, we deliberately keep the cluster total mass parametrization fixed to that of the previously published point-like mass model to enable a fair comparison. This reveals that incorporating 77,000 HST pixels reduces the uncertainty on the inferred value of the Hubble constant by a factor of 2.0, while all model realizations remain mutually consistent. Our final measurements are H_0 = 65.0^+2.0_−1.8 km/s/Mpc and $Ω_m = 0.30^{+0.08}_{-0.09}, in agreement with previous results. This corresponds to a substantially improved precision, reaching a remarkable 3.0% uncertainty on the value of H0 given our cluster total mass parameterization. The contributions of the uncertainties on the lens total mass and on the measured time delays to the final H0 error are now comparable, indicating that future improvements in cluster-scale time-delay cosmography will increasingly depend on (abridged version).
ER -