Baldwin, Phillips and Terlevich diagrams using flux measured for each spaxel with S/N > 15 in both components of the merging system. In both panels, Kewley et al. (2001) theoretical division is traced with a gray dashed-dot line. The empirical division of Kauffmann et al. (2003) is also shown in the left-hand panel with a black dashed line. The intermediate zone between the empirical and theoretical divisions in the left-hand panel is known as the composite zone.