Statistical Analysis of AGN Fraction as a Function of Projected Separation in SDSS Galaxy Pairs

Galaxy mergers and gravitational interactions are considered critical mechanisms for drivinggalactic gas reservoirs into nuclear scales, thereby triggering active galactic nuclei (AGN).In this study, we present a systematic statistical framework to investigate the AGN fractionas a function of projected physical separation (r_p) using an interacting galaxy pair sampleselected from the Sloan Digital Sky Survey (SDSS). We construct an automated dataanalysis pipeline in Python to extract emission-line fluxes and classify the primaryionization sources utilizing the BPT diagnostic diagram with the theoretical boundarydefined by Kewley et al. (2001). Our statistical analysis demonstrates a significant,monotonic increase in the AGN fraction at tight separations (r_p < 25 kpc), peaking atapproximately 14.80%, which represents a threefold enhancement compared to isolatedcontrol environments. This small-scale environmental dependency indicates a distinctphysical time-lag between large-scale tidal starbursts and the subsequent activation ofsupermassive black holes (SMBHs).