Detailed Studies of the Lyman Alpha Kinematics in 2104–242

We present Fabry-Perot observations of the extended Ly α emission around the radio galaxy 2104–242. Constraints are derived on the physical properties of the gas, including the volume filling factor, total kinetic energy, and dynamical and radiative timescales. These constraints are investigated in the context of dynamical models for the gas, such as accretion from a merger event and energy input from the radio jets. Various mechanisms for energy input to the gas are also considered, in particular photoionization by the active nucleus and shocks from turbulence related to interactions with the radio plasma.