3C 66B Binary and Jet Simulation
An interactive geometry study of the proposed supermassive black hole binary in 3C 66B, connecting a three-dimensional binary and jet model to the elliptical motions measured on the sky.
From a binary orbit to radio-core motion
The model illustrates the orbital-motion and jet-wobble interpretation proposed by Sudou et al. (2003). The two observing frequencies trace emission regions at different distances along the jet. Their motion is projected onto the sky to produce ellipses in right ascension and declination, together with corresponding time traces.
The simulation includes an oblique view, a view along the line of sight, and a binary close-up. Adjustable parameters let you explore the orbital inclination, jet orientation, core distances, and the separate contributions of orbital motion and jet wobble. A tracing animation follows one full orbit, and the model coordinates can be downloaded as a CSV file.
Reading the model
Published ellipse fits are overlaid for comparison, while assumed three-dimensional parameters are identified in the controls. The geometry is illustrative: the paper does not uniquely determine the binary and jet configuration. The page also explains the frequency-dependent core shift and why the two radio-core ellipses can have different centers on the sky.