BPT diagram. Small dots in the color scale (from yellow to dark purple) correspond to spaxels in each galaxy. Big green dots correspond to the integrated spectra of the galaxy. Next to the green dots we can see the name of each galaxy. The color of the small dots corresponds to the distance to the center of the galaxy. The closer to the center the more yellow they are, and farther away from the center they become darker. The lines that delimitate each region are taken from Kewley et al. (2001) and Kauffmann et al. (2003).