Emission-lines properties of a galaxy in the control sample (top panels, NGC 0214) and in the interacting sample (bottom panels, UGC 312). Left panels: Hα flux. White-solid and black-dashed circles represent the central and extended apertures in arcsecs and effective radius units, respectively. Middle panel: [O iii]λ 5007, emission line flux. The units in both flux maps are (log 10) 10^-16 erg s^-1 cm^-2 arcsec^-2. Right panels: logarithm of the absolute values of EW(Hα) in units of Å.