6 papers
Line-of-sight shear in SLACS strong lenses II: validation tests with an extended sample
Natalie B. Hogg, Daniel P. Johnson, Anowar J. Shajib +1
The paper extends measurements of line‑of‑sight shear in 45 SLACS strong‑lens systems, finding a mean shear magnitude of about 0.11 and showing that unusually large LOS shears are…
Line-of-sight shear in SLACS strong lenses I: shear and mass model parametrisations
Natalie B. Hogg, Daniel P. Johnson, Anowar J. Shajib +1
Inhomogeneities along the line of sight in strong gravitational lensing distort the images produced, in an effect called shear. If measurable, this shear may provide independent co…
Cosmology with the line-of-sight shear of strong gravitational lenses
Pierre Fleury, Daniel Johnson, Théo Duboscq +2
Stage-IV photometric galaxy surveys are designed to measure the position and shapes of billions of galaxies. Their aim is to characterise the large-scale distribution of matter in…
Degeneracies and modelling choices in double-plane time-delay cosmography
Daniel Johnson, Pierre Fleury, Martin Millon
Double-plane gravitational lensing is a rare but increasingly observed phenomenon in which the light from a distant source is lensed by two foreground objects at different redshift…
Line-of-sight effects on double source plane lenses
Daniel Johnson, Thomas Collett, Tian Li +1
Weak gravitational lensing perturbations have a non-negligible impact on strong lensing observables, and several degeneracies exist between the properties of the main lens, line of…
Foreground biases in strong gravitational lensing
Daniel Johnson, Pierre Fleury, Julien Larena +1
Strong gravitational lensing is a competitive tool to probe the dark matter and energy content of the Universe. However, significant uncertainties can arise from the choice of lens…