STRIDES: a 3.9 per cent measurement of the Hubble constant from the strong lens system DES J0408-5354

Understand

We present a blind time-delay cosmographic analysis for the lens system DES J0408$-$5354.

• This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide the opportunity to obtain more information at the cost of increased modelling complexity with respect to previously analyzed systems.
• We perform detailed modelling of the mass distribution for this lens system using three band Hubble Space Telescope imaging.
• We combine the measured time delays, line-of-sight central velocity dispersion of the deflector, and statistically constrained external convergence with our lens models to estimate two cosmological distances.