TDCOSMO. XXVII. JWST-based Lens Models and H$_0$ Measurement of WFI2033, HE0435, and PG1115

Year: 2026

Type: preprint

Abstract: Time-delay cosmography offers a one-step, distance-ladder-independent route to the Hubble-Lemaitre constant, H_0. We present new cosmography-grade lens models of three quadruply imaged quasars based on JWST-NIRCam/F115W imaging (WFI2033-4723, HE0435-1223, PG1115+080). We use the STARRED modeling technique, introduced in our previous analysis of WFI2033-4723, to reconstruct the complex JWST-NIRCam Point Spread Function at high fidelity. We combine NIRCam-based lens models with improved external convergence estimates, published time delays, and aperture-integrated stellar velocity dispersions from JWST NIRSpec to infer H_0. The analysis was carried out blindly for HE0435-1223 and PG1115+080, while it was not blind for WFI2033-4723, as we build upon the previous published model. For comparison with previous HST-based work, we limit our analysis to the case of no internal mass-sheet degeneracy ($λ_{\rm int}=1$). We quantify the impact of improved imaging, single-aperture kinematics, and environment measurements on central values and uncertainties. Within flat $Λ$CDM, assuming a uniform prior on $Ω_{\rm m}$, we find H_0 = 71.8$_{-7.0}^{+9.2}$ $λ_{\rm int}$ km s$^{-1}$ Mpc$^{-1}$ for PG1115+080, 74.2$_{-4.2}^{+4.2}$ $λ_{\rm int}$ km s$^{-1}$ Mpc$^{-1}$ for HE0435-1223, and 73.4$_{-4.4}^{+3.4}$ $λ_{\rm int}$ km s$^{-1}$ Mpc$^{-1}$ for WFI2033-4723. Combining the three lenses yields H_0 = 73.5$_{-2.8}^{+2.7}$ $λ_{\rm int}$ km s$^{-1}$ Mpc$^{-1}$, consistent with HST-based results (73.6$_{-2.6}^{+2.6}$ $λ_{\rm int}$ km s$^{-1}$ Mpc$^{-1}$), but with reduced scatter between the three systems. These models will be incorporated in the TDCOSMO-2026 milestone paper with free $λ_{\rm int}$ in a hierarchical fashion. We close by outlining how 16 forthcoming JWST NIRCam targets will further tighten uncertainties toward percent-level precision on H_0.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2608.27566

Authors: Williams, D. M., Treu, T., Johnson, D. P., Mozumdar, P., Knabel, S., Birrer, S., Fassnacht, C. D., Galan, A., Shajib, A. J., Wong, K. C., Cappellari, M., Courbin, F., Morishita, T., Motta, V., Sluse, D., Stiavelli, M.

Institutions: University of California, Los Angeles, Centre National de la Recherche Scientifique, Laboratoire Univers et Particules de Montpellier, Stony Brook University, University of California, Davis, University of Geneva, Research Center for the Early Universe, The University of Tokyo, University of Oxford, Tohoku University, University of Valparaíso, University of Liège, Space Telescope Science Institute

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Gordon and Betty Moore Foundation, Ministerio de Ciencia, Innovación y Universidades, Fonds De La Recherche Scientifique - FNRS, Generalitat de Catalunya, Centre National de la Recherche Scientifique, Agencia Nacional de Investigación y Desarrollo, Institut de Física d'Altes Energies, Stony Brook University, Japan Society for the Promotion of Science, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Agencia Estatal de Investigación

OpenAlex ID: W7204855039