The Archons are made using a MATLAB code which solves (analytically) two identical point vortices with opposite rotation, colliding.
Each Archon has a different set of vortex coordinates in the x,y plane and the points at which solutions are calculated is varied. Also a colour scheme is chosen.
A selection of my favourites below
contourf(xlist,xlist,w’); axis square; axis off;
And then they are edited/cropped etc.