Fast outflow of neutral hydrogen in the radio galaxy 3C 293

We report the detection of very broad H I absorption against the central regions of the radio galaxy 3C 293. The absorption profile, obtained with the Westerbork Synthesis Radio Telescope, has a full width at zero intensity of about 1400 km s(-1), and most of this broad absorption (similar to1000 km s(-1)) is blueshifted relative to the systemic velocity. This absorption represents a fast outflow of neutral gas from the central regions of this active galactic nucleus. Possible causes for such an outflow are discussed. We favor the idea that the interaction between the radio jet and the rich interstellar medium produces this outflow. Some of the implications of this scenario are considered.