From left to right: VLA and HST observations (VLA: white contour lines, HST: colored map); emission-line gas and radio plasma from helical strings in the Seyfert 2 Galaxy ESO 428-G14 (Falcke et al. 1996, for the scale: the image covers about 0.4 arcsec); the double helix nebula (Galactic center) observed at infrared wavelength of 24 μm with the MIPS camera on the Spitzer Space Telescope (Morris et al. 2005); and a multi-color optical image around the ULX “X-1” (indicated by the arrow) in the dwarf galaxy Holmberg II. The red color in the image (right) represents spectral line emissions from hydrogen atoms (courtesy of the Special Astrophysical Observatory/Hubble Space Telescope). The image size corresponds to 1100 × 900 light-years at the galaxy.