INFRARED K-BAND OBSERVATIONS OF THE GRAVITATIONAL LENS 2016+112

Infrared observations of the gravitational lens 2016 + 112 at the K band (lambda = 2.2-mu-m) are presented. The infrared image is dominated by the extended emission of the radio quiet foreground galaxy, which acts as the gravitational lens. Infrared flux is seen at the location of all three radio loud components of the system. Gaussian fits to the data yield K-band fluxes for all four components. To within the errors of the fit, the i - K colors of the radio loud images are similar, while the color of the foreground galaxy is closer to that expected for an elliptical galaxy with z approximately 1. The relative brightnesses of the 2016 + 112 components at K band are significantly different than the optical g-band brightnesses. The K-band observations suggest that the central galaxy makes the dominant contribution to the mass acting as the gravitational lens. A model of the gravitational lens as a single massive elliptical galaxy is presented. This model suggests that all radio loud components of 2016 + 112 can be explained as images of the background quasar and are not due to a second foreground galaxy, as indicated by earlier work. Radio wavelength observations at the X band (lambda = 3.6 cm) are included to show the compact radio structure of 2016 + 112, which also supports the single galaxy lens model.