Radio and infrared structure of the colliding-wind Wolf-Rayet system WR 147

New, high-resolution IR and radio images of the X-ray-luminous Wolf-Rayet system WR 147 (AS 431) are presented. The 5-GHz radio image resolves both components of this double source. The emission from one component, that to the south and associated with the wind of the WN8 star, has an extent of about 170 x 253 sq mas, indicating that the stellar wind is not spherically symmetric. The second, nonthermal component, about 0.6 arcsec north of the WN8 star, is extended east-west to about 267 mas. The IR image reveals the presence of a companion to the WN8 star, close to the nonthermal radio source but slightly more distant from the WN8 star. The companion is Delta-K of about 3 mag fainter than the WN8 star and has the luminosity of a B0.5V star, just sufficiently luminous to possess a stellar wind capable of colliding with that of the WN8 star. The presence of the nonthermal emission between the two stars and much closer to that with the weaker wind is direct evidence for a colliding-wind origin for the emission. A significant portion of the X-ray emission can also be accounted for by the release of energy in the wind collision. (Author)