Abundance gradient in NGC 5427. The oxygen abundance (see Fig. 7 and Table 1) is plotted against deprojected distance from the nucleus. Region 35 is left out, as the abundance has a large uncertainty. To compute the deprojected distance, it is assumed that the galaxy disk of NGC 5427 has an inclination of i = 38deg and a position angle of PA = 11deg (cf. Marinova & Jogee 2007). The line shows a linear regression. The linear regression results in a gradient of –0.025 dex/kpc and a (maximum) central abundance of 12 + log (O/H) = 9.25, typical for galaxies in their early tidal interaction phase.