The Hubble constant inferred from 18 time-delay lenses

TL;DR

This paper analyzes 18 galaxy lenses with time delay data to estimate the Hubble constant, finding values around 66 km/s/Mpc generally, but higher for a specific subsample, contributing to cosmological measurements.

Contribution

It introduces a simultaneous pixelated modeling approach for multiple lenses to infer the Hubble constant, including a subsample analysis with additional constraints.

Findings

Estimated H_0 as 66_{-4}^{+6} km/s/Mpc for the full sample.

For a subsample of isolated galaxies, H_0 is 76 +/- 3 km/s/Mpc.

Demonstrates the effectiveness of joint modeling in lensing-based cosmology.

Abstract

We present a simultaneous analysis of 18 galaxy lenses with time delay measurements. For each lens we derive mass maps using pixelated simultaneous modeling with shared Hubble constant. We estimate the Hubble constant to be 66_{-4}^{+6} km/s/Mpc (for a flat Universe with \Omega_m=0.3, \Omega_\Lambda=0.7). We have also selected a subsample of five relatively isolated early type galaxies and by simultaneous modeling with an additional constraint on isothermality of their mass profiles we get H_0=76 +/-3 km/s/Mpc.