Change the conditions

Lens setup

1.0Tsolar masses2.85″reference scale

Source alignment

Move the distant galaxy through the lens caustics.

Horizontal offset+0.00 θEVertical offset+0.00 θE

Lens and source

Set the total bending scale and source extent.

Lens mass1.0 trillion M☉Sets the reference Einstein scale for the combined mass.Source size629 mas

Mass distribution

Separate starlight from the larger dark-matter potential.

Stellar ellipticity0.00Flattens the visible galaxy and its stellar potential.Dark-matter share62%Blends the compact stellar lens with an extended NFW-like halo.External shear0.000Tidal gravity from nearby galaxies and structure.

Structure and guides

Reveal what shapes the ray-traced image.

Satellite subhaloA small dark clump that locally perturbs the arcsShow foreground lensThe luminous galaxy inside the full mass modelShow ray-tracing guidesCritical curve, mass contours, and source position

Interactive simulation

Gravitational Lensing

Shoot light backward through an elliptical galaxy, its dark-matter halo, and nearby tidal gravity.

2.85″Einstein angle62%dark halo

Drag across the skyMove the blue source behind the golden lens

Find perfect alignmentCompare rings, four images, and fold arcs

Ray-traced configurationNear-complete ring

Extended massLensed source