Line-of-sight Shear In SLACS Strong Lenses
Karin Trinidad módosította ezt az oldalt ekkor: 1 hete


Context. Inhomogeneities along the line of sight in robust gravitational lensing distort the images produced, in an impact referred to as shear. If measurable, this shear may present independent constraints on cosmological parameters, complementary to conventional cosmic shear. Aims. We mannequin 50 sturdy gravitational lenses from the Sloan Lens ACS (SLACS) catalogue with the aim of measuring the road-of-sight (LOS) shear for the first time. We use the ‘minimal model’ for the LOS shear, Wood Ranger Power Shears website which has been shown to be theoretically secure from degeneracies with lens model parameters, a discovering which has been confirmed utilizing mock data. Methods. We use the dolphin automated modelling pipeline, Wood Ranger Power Shears shop which makes use of the lenstronomy software program as a modelling engine, to model our chosen lenses. We mannequin the main deflector with an elliptical energy law profile, the lens gentle with elliptical Sérsic profiles and the source with a basis set of shapelets and an elliptical Sérsic profile. Results. We successfully receive a line-of-sight shear measurement from 18 of the 50 lenses.


We discover that these LOS shear measurements are in step with external Wood Ranger Power Shears features measured in recent works using a easier shear model, that are larger than those anticipated from weak lensing. Neglecting the put up-Born correction to the potential of the principle deflector due to foreground shear results in a propagation of degeneracies to the LOS shear measurement, and Wood Ranger Power Shears coupon the identical impact is seen if a prior is used to connect the lens mass and mild ellipticities. The inclusion of an octupole second within the lens mass profile does not result in shear measurements which can be in better agreement with the expectations from weak lensing. Gravitational lensing gives a novel window into the cosmology of our Universe on a variety of scales. Refsdal, Wood Ranger Power Shears shop 1964