Doppler tomography of Balmer lines from the Keck observations. The positions of the primary and secondary are indicated by plus signs (+), and the center of mass of the system is labeled by a “x” mark. The solid lines represent the Roche lobe of the secondary and the stream trajectory. Color scales indicate the normalized flux. The dashed line represents the radius of the tidal limit of the accretion disk. Left: Tomography of Hα lines. Right: Tomography of Hβ lines.