Project Leda


Probing the dark matter distribution on scales of a few hundred parsecs requires a high angular resolution of a few milli-arcseconds. Currently, this is only provided by interferometric arrays at cm and mm-wavelengths. In order to analyse this type of data, this ERC-funded group has developed a new lens modelling code that fits the data directly in the visibility space. By applying our technique to milli-arcsecond angular-resolution data taken with the Global Very Long Baseline Interferometer network we have set competitive limits on Fuzzy dark matter. Currently, we are derving, from the same data, constraints on the halo mass and subhalo mass function. At the same time, we have developed al ens modelling code that allows us to simultaneously and self-consistently constrain the polarised properties of the lensed source, the mass distribution of the lens and the properties of its magnetic field.


Simona Vegetti
Simon Ndiritu
Devon Powell
Hannah Stacey


Complex angular structure of three elliptical galaxies from high-resolution ALMA observations of strong gravitational lense .
Stacey et al. submitted, 2023arXiv230611781V

A lensed radio jet at milli-arcsecond resolution - II. Constraints on fuzzy dark matter from an extended gravitational arc.
Powell et. al (2023), MNRAS, 524, 84

A lensed radio jet at milliarcsecond resolution I: Bayesian comparison of parametric lens models.
Powell et. al (2022), MNRAS, 516, 1808

A novel approach to visibility-space modelling of interferometric gravitational lens observations at high angular resolution.
Powell et. al (2021), MNRAS 501, 515

The rocky road to quiescence: compaction and quenching of quasar host galaxies at z ∼ 2.
Stacey et. al (2020), MNRAS, 500, 3667